|S2Ks still go for $10k on average for one in OK/decent shape. That's just under a nearly new NC Miata (~$10k+).
Compare the cost of an S2K with either an NA ($2000 for a very decent one) or NB Miata ($4000 for a very decent one), there's no comparison. Especially when you add in cost and ease of forced induction.
I'd much rather have an S2K from a looks standpoint. But from a performance and performance/cost standpoint, not a chance.