...a salvage car is a very bad idea unless you've a lot of money, time, and expertise to carefully choose exactly the right car and view the process of restoring it as more enjoyable than having the car to drive...most salvage-title cars with frame damage cannot be repaired at all, and even those which can will end up costing significantly more than to buy a good-condition car outright...
...i don't recommend buying an elise until you have a private garage to keep it in every night and are confident that you can comfortably afford the insurance - at your age it can be brutally expensive for these cars...of course there are exceptions, but most people are not in a position where they can really afford the ownership of an elise or exige any earlier than their mid-twenties...
...a lot of people go with something inexpensive and expendable for their first six or eight years of driving, like an MX-5 or MR-2, just to get some solid high-performance driving experience in an excellent-handling car while awaiting a better-suited opportunity to own a high-line sportscar like a lotus...in fact, you'll find that a preponderance of the better drivers on this forum developed their skills in one of those two cars, an opportunity i wish i'd had when i was younger...