Well, first you are right, the price of a BT keyboard and Mouse are expensive. I am using Apple's BT keyboard and Belkin's BT Mouse (best price I found for the Belkin was around $77 at
www.eCost.com). I have very happy with the combo. I personally perfer Apple's Keyboards and I have programed the mouse to take atvantage of Expose'. The Belkin has the same button layout as the older Logitech MouseMan Optical, R, L, Scroll wheel and thrid button, and a fourth button on the left side where a RH person's thumb would be.
You're seniro is not possible, sorry.
Oh, one draw back on the Belkin BT Mouse is that there is no off switch like on Apple's mouse, something you just have to figure out or replace batteries more often. I use rechargable batteries.