I got on this when it was a 2000+ (TBred A) for $69.99 with a free HSF, I think the $79.99 in CA was for the 2200+ not the 2400+ (that's $89.99).
I found the K7S5a Pro to be a great board - XP loves it, the only thing I had to install manually was the USB2.0 (high speed) drivers. Mine was a Rev. 5 board, so these are not old boards. Make sure you're getting the Pro board as the non-Pro is crap.
People have said that it needs a good PSU (I have a 400W) and sometimes has issues with SDRAM - although I am using a mix of PC150 and PC133 and it works fine - in fact the PC150 won't work on my KK266-R, and you can always use DDR....
Also, I've heard USB2.0 only works reliably with XP although there are 98SE and 2000 drivers - but there area shedload of USB1.1 ports anyway....
Personally I've not seen any of these issues and am very pleased, I'm actually thinking of taking up this new deal
Edit: as far as the install problems go - what OS are you trying, as I never needed the CD in XP Pro. Also, I had to set the reset CMOS jumper to even get the board to POST.....