Well I've just been looking.
The one I'm looking at right now is the TRENDnet TK-210K 2-Port USB and PS/2 KVM Switch with Audio.
http://www.newegg.com/Product/Product.asp?Item=N82E16817107247
I did notice that someone made a comment in a review about mice but wasn't specific.
"Pros: Size, reliability.
Cons: Darn beep, but you get use to it. Certain mice don't always work with it."
What I wonder is, if this won't work is there any that work perfectly that cost less then 100 bucks?
I actually continued reading and it looks like someone was able to get their wireless MX 700 mouse to work properly with all the buttons with some tweaking. Also someone mentioned with this they had to do some tweaking to get good quality video from it, I hope their tweaking wasn't lowering the resolution. I know it seems like a lot of KVM's video quality isn't so good when you use high resolution.