In our case here, since the Wii was purchased at launch, there were several factors. For the price aspect, we didn't want to pay more than the Wii, AND we wanted a non-nerfed system. (Thus the Arcade 360, with no HDD, was out.) We also wanted a number of games that we would all be interested in for the system. The 360 did it, mainly with XBLA and a few retail titles, coupled with the fact that when the Pro was being phased out, the price drop made it look a bit better. Add to this, a store that we shop at often (MicroCenter) offering a $50 giftcard with purchase of a 360, made the system down to $200 for us, the sweet point to getting it. And now we've slowly been picking up games for it too... we just need to get the time to play them and get them off the backlog...
So I guess, the price would be $200 with all features intact. And games that interest us. Unfortunately, I think the PS3 has been permanently ruled out here, since the ones with PS2 backward compatibility aren't going to be that cheap in working order... (And before anyone complains about the B/C request, the PS2 had to pick up that slack when PS1 #4 died. We picked up a spare PS2 for when, not if, the current one we have dies. I can't remember if the current in-use PS2 is #2 or #3 anymore...)