Recommend a Hardware Keylogger?

I need 5-10 hardware keyloggers. I'd like to keep it under $45 each. I'll buy 1 to test then hopefully get a deal on a bundle.

I think the USB ones would be better since it would catch mouse stuff as well as the keyboard. I assume the ones that are inline with the keyboard plug only do the keyboard? I've never used one.

Anyway, if someone here has an opinion or recommendation for a reliable source I'd much appreciate hearing it

TIA

I can recommend you ProteMac KeyBag.
It costs 50$.

I'm monitoring our family PC with this device bought at microspygadgets.
I'm using it for 8 moths and it works perfect.

Hmm, why do you need hardware keylogger?
Keylogger software is not enough?