here's a good breakdown on the "affordability" of a viper. I recently bought a very low milage 99 viper rt-10, and it was the cheapest "decent" sports car I could buy. I compared the "cost of ownership" against a new Honda S2000, or a used BMW M3; the viper was cheaper.
Insurance was identical, basically all sports cars worth owning are in the top bracket.
The matainence cost is higher on a viper, say 1000 more a year.
The depreciation is next to nothing on a viper, all other cars I looked at would be depreciating at a rate of 2k a year.
The viper was only about $10k more, which equates to about $500 a year loss in investment income.
Add it all up and the viper is costing me $500 less a year than a new honda s2000, or almost any other more common sports car.
The only better buy is a C5 Z06, but not buy much, and then you'd be seen driving a vette. :-0