i have a 92 berretta GT that has some customization done to it, i bought it used from a private owner a year ago and im still finding problems. since ive had the car i have had to replace the feul pump and the heater core, which isnt expensive but, i recently found that when the previous owner lowered the car he heated the springs and now they collapsed onto themselves. my question is would it be worth it to replace the springs or to buy another car and start from scratch and put my own modifications on???  

Your best bet if your trying to be fast on the cheap is to lose the FWD NA Beretta GT, and buy something that isnt FWD, and is preferably turbocharged/supercharged from the factory or has a v8.  

The problem is that your car has no performance parts to speak of. Sure old cars like those are great for modifications, because no one will care what you do to them, or if a single modification is worth more than the price of the car itself but when there's so little backing and fake E-Bay parts start comming around. Whatever lure that car had is not turned into a rolling eye-sore of biblical proportions.

I recommend a new car that appeals to you.  

my problem is i am extreamely short on money and i havent a new job, and i was thinking about buying an old 80s model toyota supra but ive had no luck finding any in a good price range that isnt a hunk of junk, would that be a good buy if i could find one???  

the mk3 supra (86.5-92) is a very nice car, capable of building decent power, RWD, turbo (if you can find one with it), and the 7MGTE is near bullet proof if it wasnt for the supras notorius problems with blown head gaskets.  for a good condition running mk3, youd prlly be able to find one for round 3500 or 4k. for one with a BHG, 1k to 1500.  the head job isnt all that hard (ive done 3), but if you wind up with one with a BHG, spend the money one a metal head gasket, and arp head studs. (arp head bolts if you dont have the ability to pull the engine)

heres a supra specific forum with all of the info youll need about supras

www.toyota-supra.info/forums/