I've had my 200 for many years and it's been stupendously reliable and great fun to drive.
They're only expensive if you start chasing silly power (as is any car).
If you're into scoring Internet Scene points then it can get expensive too (as is any car).
You'll struggle to find a car that offers better value for money.
Just drive one first, they're GT cars so not going to be super precise like an MX-5 but they're still fun to drive, especially if the suspension is tweaked slightly (for not a great deal of money) and the sweet spot is around 300bhp apparently. Weighing ~1200kg and ~300bhp makes for pretty decent performance with low running costs. Most of them are modified now, you just need to buy one that's been looked after, this is probably quite a challenge these days.
If you can find something that is faster, more reliable and more fun to drive for the same total cost of ownership then I'm all ears.
The only real upgrade for me is the E46 M3 but I fear they're getting a bit old in tooth now and clearly the running costs dwarf that of the Nissan, not to mention they cost twice as much to purchase.
FWIW the S15 is overpriced for what it is....IMO.