BadBoyGreek :
Best option right now IMO are the Corsair ML series 120 and 140 mm fans. Not sure how much you know about them, but they're the first PC fans using maglev technology and they're much quieter due to no contact with the bearings. Been using them myself for about 6 months and they're great.
I think right now you can get a pack of 2 of the 120mm fans in the ballpark of what you're willing to pay, while the 140mm variant goes for about $25 each.
Note that you have to be very careful with the ML Pro fans. If you connect them to the wrong type of header, or the right type of header with the wrong implementation, you can destroy the bearings in those fans. The damage occurs over time, usually. Power outages can take them out in one fell swoop, just like an improperly installed water pump.
It's enough of a pain to ensure they'll work that I hesitate to recommend them, even though they perform very well when you do your homework and install them correctly.