I have not done any paint work on my '73 914 yet, but I have experiance doing it (several times) on a Mustang and Stealth. It sounds as though you are not painting it yourself, but I would consider it. At any rate here are some generic tips that could help you save some money.
1) Do all bondo work yourself, make sure you sand it smooth, and that it melts with the rest of the car.
2) If you want the paint to last a long time, give a good finish, and not rub off on anything it touches, I recomend sanding all the paint currently on the car down to the metal, doing this yourself will save you money, and its very easy (time consuming) to do.
3) If you feel up to that task, prime the car yourself. Once primed, you can always sand the spots that came out bad. Make sure to wet sand after you finish the prime coat.
4) Now to really save money, paint it
Once painted (two or even 3 coats) wet sand it.
It only cost me about $200 for a complete paint job on the Mustang. The Porsche has a little less surface area, so depending you may get out cheeper (doubt it, there pretty close). I don't know what your paying for a paint job there, but for an equivalant one here, same color and same area (inside and out) they wanted $1200. I could repait the car 6 times and still break even, so if you mess up, you can always do it again. Plus think of all you will learn. If you want some more specific advise on painting, let me know and I'll do what I can. Good luck!