This leads me to my first point. I feel that at the beginning you must decide if you want to buy a car that someone else has done up, or do you want to tackle the job of restoring on your own. There are pluses and minuses to both. The term restored is over-used and I would tend to ignore that term altogether. When looking for a car that you can just jump into and drive away, be prepared to pay for it.
Someone has to pay for the labour, time and money spent on the car.
I do find it is generally far cheaper to buy a properly restored car than having to do it on your own. This only makes good sense however, when you're able to check the quality of work that has been done. Find out what shop did the work and go there to see what other cars look like while being worked on. If a car is stuck in the corner piled high with cardboard boxes and oily rags, rest assured your potential buy suffered the same fate. While there, tell them what you are doing, the shop workers are bound to tell you some of the cars history the owner doesn't.