Case Fans

I just installed a replacement 60mm exhaust fan (it is optional with this case), and was wondering, how long should a fan last if a system is being used say 24/7 (not powered down)?

I bought two of them (so I have a spare), but does spending more moola equate to longer lasting (the two fans I bought are by masscool and I paid $2 apiece for 'em).

Any thoughts (I know they are a consumable)

At those prices I'd probably rather replace than clean them when they're due . Here case fans last ~1.5-2 years.
The higher priced ones don't necessarily last longer but they usually run quieter (better bearings) and might even shovel more air (different shaped blades). But if the noise level doesn't bother you stick with the cheap ones. They're not as important as heat sink fans so IMHO it's ok to lower the standards.

-DG

i replace my fans after about 6 months, no idea why to be honest i just do

they should last as long as sledge mentions without any real issues.