Paying someone to do an entire resto is a no-win situation. If you find someone who will do it right, you will pay out the nose for it. We're talking $20K plus for a good restoration of a complete car with the typical rot, and that's probably low. If you strip the car yourself and take just the body down to get the bodywork done, you're in better shape. Still, there are no good $5k paint jobs when you are paying someone else to do it! Consider my '72 cuda which I replaced the floor pans, quarter skins, trunk pans, lower door skins, and had to fabricate misc. other pieces. I have around $1k in parts, $1k in blasting and prep materials, and I'll have another $2k or so in paint and paint prep materials. That's me doing all the work (exept the media blasting). The other thing about having someone do the work is that they typically won't do it as well as you would do it, even if you have only marginal skills. The time it takes to get everything just right and not cut corners is just mind boggling. The guys that will do the resto right in a reasonable amount of time will charge a hefty sum. In the case of the '72 and up cars, you can quickly spend more on a restoration than on buying a car that was done well.
I think there are some key points to think about before starting a restoration:
1. What do I want out of the car (show, nice driver, money)?
2. How long do I want the restoration to hold-up?
3. If the car looks like it has a poor paint job and poor body work, will that bother me? (There's a difference between concourse restorations, "show" cars, nice cars, and cars that look like they were poorly restored.)
4. How much can I do myself?
5. How much can I spend?
6. How much can I spend beyond the market value of the car?
7. How long can I wait to get the car done?
The beauty of buying a car that is already done is that you know what the car looks like, you can have it reviewed by an expert prior to purchase, and you will probably have some history on the car. You know what you are buying and what you are paying. The risk, if you buy right, is very low (i.e. if you don't like the car or you need to sell it, you can get what you paid.) If you pay someone else to do the restoration, you won't know what you are getting until you get it. Sure, you might see other exmaples of a guy's work, but the proof is in the pudding. If you do the car yourself, you have control over the quality, but it will likely take a long time to get the car done. The value of the car might cover your out of pocket expenses, but you will never get paid for your labor (that's ok...I look at it as a hobby and all hobbies have a price). You will have a tremendous amount of satisfaction if you do the car yourself.
Doing restoration work is very rewarding and you'll be surprised at what you can do yourself if you read and learn.