I have some case fans that I bought for a project and never finished. I paid $12 ech for them, but had to buy 10. I have 7 left. They are super quite and have the 4pin connector. Great for hooking up to your mother board which allows you to control the speed. I have one in my computer which keeps it running at 89 degrees. So quite you can't even hear it running.

Asking $4 ech