Phil's right as usual...
Phil makes a good point. Depending on what you include in "restoring" your vehicle, you can easily exceed the value of the car with a simple (but correct) paint job. The "more door" cars don't command as much value as the two door coupes and the convertibles. Two door sedans are neat, but also seem to be less desirable that the coupes and converts.
Four door cars, especially those with posts (the sedans) are at the bottom of the list in terms of buyers looking for them and paying for them.
Depends on how you're into the car, what you can clean her up for, and then finding a willing buyer. Remember, it costs just as much to hang a new exhaust on a $500 car as it does on a $50,000 car (well, almost!) and one commands a greater margin of profit. In general, it is really hard to make a profit on any serious restoration that includes mechanical refurbishing, good paint and a new interior, unless you are charging "shop rates" from a customer. At least that's what I think, but then I rarely sell things...
Good luck!
TomK