I've said it before, and I'll say it again, higher displacement CAN be better, but I'll take a smaller more volumetrically efficient engine any day.
If you paid too much for parts, yes it would be over 5k in parts. The nice thing is so many people start these projects and don't finish them that parts can be found for dirt cheap.
This whole thing started because I said I thought DSMs were the best BUDGET performance car. I still think they are. Are there better cars out there? Ofcoarse. Could someone build a different car faster for less money? Sure, given the right circumstances. My only point was that these cars are everywhere. They are a dime a dozen. You can buy the car cheap, you can buy the parts cheap, and if you spend the time there is TONS of proven info on how to make them fast. My intent was never to convince you to ditch your Mustang and buy one of these. If there were a competition where I was given 5 grand and told to make a fast car, I would start with a 1st gen DSM.