I have never done a crapcan race before but I have raced an ITA car for 4 years. I have done the challenge twice.
I made money on both challenge cars when I sold them after the event. In fact I almost doubled my money on the BMW engine RX7.
It would seem that you could get an inexpensive SCCA legal IT or NASA classsed car for the same price that you guys are mentioning for a crap can car. (I sold my sorted ITA MR2 for $3900 a few years back) Other then the track time advantage it would seem a more traditional club racing car would be a better investment. You could use it for a long time and sell it for what you bought it for as long as you don't ball it up or buy a built engine etc.
A typical SCCA weekend between Practice, Qualifying, Enduro race nets a pretty decent amount of track time as well and has lower entry fees.

