I restored cars for clients for about 14 years , the price doesn't change much , I worked for far less than I should have but passion is passion , the #s don't vary by much , Engine builds , body & paint interior etc are similar . Even better aftermarket parts vs original can be similar in price .
Where the difference comes in is how much work you do yourself & how complete the car us when you start , locating impossible to find parts drive up the price .