Replying to Car help

i found a guy selling one with like 120k on it for 3k, and will go lower
after going on kbb.com i looked at the specs to see hp, and gasmileage, and it said it needed turbo gas.
what is the difference between this and regular gas? how big is the price difference?
is this a good deal
(im loooking for a ski/school car to last a good while thru college and then some, how long do ssaabs generally run till, like 250k?+or -?)

i posted this in the car cult, but it will get more views/responses here

thanks