A quick look around eBuyer is a dangerous thing

For £7.77 inc VAT but ex delivery, you can have an Anterc 120mm
http://www.ebuyer.com/product/247977"Antec's TrueQuiet fans bring proven cooling and Quiet Computing™ to your system. Constructed for versatility, TrueQuiet fans include a convenient 2-speed switch that allows you to easily choose either silent or maximum RPM cooling. Because a functional computer relies on more than just cooling, TrueQuiet is equipped with silicone grommets and a uniquely-designed fan blade to reduce turbulence, vibration and noise for overall quiet operation. TrueQuiet comes in two models, 120 mm and 140 mm fan, and is backed by a 2-year limited warranty on parts and labor. Upgrade your fans and add optimal cooling and functionality to your PC with TrueQuiet."
Which got the following reviews...
"great fan and very very quiet, the yellow gromit/thingys in the picture are actually rubber and you don't get screws with it either, you get little plastic arrow head type plugs for quick installation, i have it plugged into a molex connector and not the mobo and still can't hear it, it also has a little switch to alter the speed, all in all i'm very happy, and also very happy with ebuyer for a very quick delivery (ordered sat 29/1/11 came monday 31st with super saver) Thanks guys!"
and...
"I've had an Antec P180B case for over four years now and the case fans were getting a bit noisy. I decided to replace them with 3 of these fans, though the top exhaust fan wouldn't fit due to it having two 'hooks' at one end. That's more of an issue with the case rather than the fans however.
The other two fitted fine and are significantly quieter than the OEM Antec fan units. Having those yellow rubber attachments presumably cuts down on chassis vibration too. Well recommended - certainly at this price."
Oddly though, they don't specify the dB levels.
For £4.23 inc VAT but excluding delivery, you can have a Xilence Black 120mm
http://www.ebuyer.com/product/151390"Technical Data
Dimensions: 120x120x25 mm
Voltage: 12 VDC
Starting voltage: 6 VDC
Power consumption: < 1,2 W
Rated current: < 0,10 A
Fan speed: 1.400 RPM ±10%
Bearing type: Hydro bearing
Max. air flow: 48 CFM Air pressure: 2,3 mmAq
Noise level: 21,2 dB
Weight: 140 g
Connectors: big 4pin (HDD), 3pin Molex"
And there are 11 reviews, but here's a couple...
"These come retail boxed, not just in a bag. Supplied with case screws. Both 3 pin motherboard header and 4 pin molex. I have two of these on the front on my case and they are very quiet. On about half speed they are pretty much inaudiable. Even on max they are pretty quiet. Definately recommend these and will probably get another for the side of the case. May even replace the Antec supplied fan with one of these too."
and...
"In my haste i picked these fans as they seemed like a low noice, high CFM ratio with a good value. Note that the packaging states that these are 44.71 CFM and they are a tad quieter than stated at 20.5 db "
For £13.07 inc VAT excluding delivery there is a Coolermaster 120mm
http://www.ebuyer.com/product/218936"Excalibur, as the name suggests, is inspired by the legendary sword of King Arthur from the middle ages. The nine massive sword-shaped blades are designed to produce exceptionally high air pressure, which fortify the cooling efficiency when used in dense water cooling radiators or performance heatsinks.
This is the first fan from Cooler Master to adopt Barometric Ball Bearing (BBB) technology.
Features
The innovative Barometric Ball Bearing technology provides longer life span while remaining lower noise level.
Removable blades for quick and easy cleaning.
Nine massive sword-shaped blades generate outstanding high air pressure with balanced airflow.
Triangular blade tips reduce turbulence at fan edges and decrease wind shear noise while keeping maximum sweeping area.
3-piece frame with metal rim provides robust structure.
Honeycomb ventilation meshed frame:
- Low speed operation works as a secondary intake to increase airflow.
- High speed operation helps to reduce noise by releasing excessive turbulence and vibration.
PWM function for total performance solution at high and low speed operation.
specifications
Dimension 120 x 120 x 25 mm
Speed (R.P.M.) 600 - 2000 RPM ± 10%
Air Flow (CFM) 26.4 - 85.6 CFM ± 10%
Air pressure (mmH2O) 0.75 - 3.53 mmH2O
Noise 13 - 30 dBA
Bearing Type Barometric Ball Bearing
Fan Life Expectancy 100,000 hours
Voltage 12 V DC
Current (Ampere) 0.45A Max.
Power consumption 6 W Max.
Weight 127.8 g
Connector 4 Pin
Accessory Rubber screw x 4
Metal screw x 4
Rubber pad x 4
4-to-3 Pin adapter x 1"
This review mad for interesting reading...
"I'm a little undecided on this fan after purchasing it. I orignally ordered it with intentions of fitting it to my H50 rad, dont bother... even though there is a higher static pressure to most other simalar spec fans, I was seeing higher temps with this than I do with the antec tri-cool on max... with this fan being louder than the tri-cool.
The fan does a good job as an intake fan, which it is now, and would do amazing as extract if no H50 was involved. Nice high CFMs Static Pressure and lush design, good accessories too. Bit loud on max but I can get used to it, or slow it down with my fan controller. I do recommend buying for a case fan and not for H50 rad... next best bet would be Akasa AK-FN059 120mm Viper Fan, for specs at least."
How about some Cougars?
£9.06 in vat excluding delivery
http://www.ebuyer.com/product/269173" Optimum cooling efficiency and silent performance
Diversion groove blade design
Aerodynamic design to reduce air turbulence
Airflow optimised Nine blade design
Airflow 60.4CFM at 17.7db (1200rpm)
Air pressure 1.73mm H2O
Acoustic noise 17.7db
Life MTBF - 150,000 hours
3pin adapter with 3 to 4pin adapter
Bearing - Hyper-spin
voltage range - 6-13VDC
Speed - 1200rpm"
£14.61 in VAT excluding delivery
http://www.ebuyer.com/product/269164" High vortex airflow with turbine blades and frame design
Optimum airflow and extremely quiet operation
Diversion groove blade design
focuses airflow for optimum cooling efficiency
anti-vibration pad design
aero dynamic design - reduces air turbulence noise
Flexible PWM design -motherboard controls the speed 800-1500rpm
Hydro dynamic bearing design - runs quiet and durable
high quality IC controls the motor - minimisation of electrical noise
Specifications:
120x120x25mm
Speed - 800-1500rpm
Bearing - Hydro Dynamic Bearing
Voltage range - 4.5-13VDC
connector - 4pin pwm (including pwm to 4pin adapter)
Life MTBP - 300,000 hours
Acoustic Noise - 17.3db(a)
Air pressure - 2.2mm H2O
Airflow - 70.5CFM 119.8m3/h (max)"
£13.10 inc VAT excluding delivery
http://www.ebuyer.com/product/269169"Product Description
High vortex airflow with turbine blades and frame design
Optimum airflow and extremely quiet operation
Diversion groove blade design
focuses airflow for optimum cooling efficiency
anti-vibration pad design
aero dynamic design - reduces air turbulence noise
Hydro dynamic bearing design - runs quiet and durable
high quality IC controls the motor - minimisation of electrical noise
Specifications:
120x120x25mm
Speed - 1200rpm
Bearing - Hydro Dynamic Bearing
Voltage range - 4.5-13VDC
Connector - 3pin with 3 to 4pin adapter
Life MTBP - 300,000 hours
Acoustic Noise - 17.7 db at 1200rpm
Air pressure - 1.73mm H2O at 1200rpm
Airflow - 60.4CFM at 1200rpm"
So 17dB is quiet and 30dB is a bit loud. But the numbers mean nothing to me. But by the power of Google I can show you this...
http://www.industrialnoisecontrol.com/comparative-noise-examples.htmSo 30 dB is "Quiet rural area", and 20 dB is "Whisper, rustling leaves".
Happy shopping
