You want to make a cheap small 2 door look even cheaper? Why?
Save your money and buy a nicer car instead of modding an older model cheap car. Modding an older model will just make the value of it go down and i've learned from my own research.
Just to answer your questions, i think you could do all the mod's in your first question for about 2 grand. That's with cheap parts though. A cheap body kit is going to look like its falling off and a cheap exhaust is not going to do anything to the performance like you expect. Save the money, buy real performance parts for a real or at least a newer car.
Second, it sounds like he shaved(that's what it's called) his door handles off and either made them hard to see or electronic. This can be expensive if you want it done right. I didn't even bother looking into this but my guesstimate would be around a grand maybe. I really dont know and the best way for you to find out would just be to ask him.
HTH