Jordan,
To answer your question regarding a starting point, it really depends on what your objective is. For example will it be used mainly as a driver, semi-show or full show car. You are right in saying that the term economical doesn't often enter into the picture though.
For a car that you plan on using mostly as a driver or cruise nights, etc. I agree with the observation that Larry made about finding a good car either without an engine or one that has an NOM. It can be an easier route to take and can well be the less expensive one in the long run although you will pay more up front. You'll often find that the owner of those cars may not be able to get back all they have invested and that's to your benefit. You can also defray some of your costs by selling those parts you will no longer be using such as the drivetrain and suspension.
If you plan to redo everything anyway you can start with something that isn't as good, presuming that all or most of the major parts are there, and you may be able to find one that's less expensive. The one I started with had most of the parts, minus the engine, but everything needed to be redone. The paint was blistered, the interior was trash, the windows were cracked, the chrome needed to be redone, etc. but it was what I wanted as I planned to redo everything anyway. It does add to the length of the project though.
Of course, all that is good in theory as you have to take what you can find out there for a starting point and go from there. Either way will work but I wouldn't suggest starting with a real basket case as you'll often find major pieces missing and lots of surprises. Those are the things that kill from a cost standpoint and they also add to the frustration you'll encounter. These projects should be fun and you don't want to go down that road if you can avoid it.
This type of project is really two projects in one. The conversion of the drivetrain and suspension can be very involved but you also have the restoration aspect depending on how good your starting point is. As Larry mentioned a good plan based on your research is key to ending up with the car you invisioned at the start. Even with that there will still be those things that are unforseable but that's part of the fun in doing something like this.
If you are ever interested in building one just let me know as I'd be glad to help.
Rich Lagasse
ps: We'll see how Vette magazine follows through on the vintage race cars. From what they said in the response there should be more coverage than in the past.