I think 80% is probably top dollar on a custom rifle unless the maker dies or retires. Why buy yours if I can buy the same rifle for the same price and have it made especially for me with my preference of finish and LOP. Once they stop making them, the price starts to shoot up.
There is no way I can spend $4000 plus on a rifle. If you buy a McMillan rifle, they will let you attend one of their shooting schools and I think they will let you come back as often as you like which is really cool except for the fact you have to spend $4500 on a rifle.
I started a build on a savage 110 action. There is no way I will get my money back out of it and by the time I'm done, I probably could have bought a better rifle for cheaper. So far, I got $250 in the action, $250 in the barrel, $200 in a stock, and $200 in smith work. I still got to get a trigger and another stock. Trying to fit a rifle in a stock with aluminum bedding blocks can be a serious pain if the bedding blocks are in the way and need to be cut or shaved down at all. If I get a smith to fit it, the stock will end up costing me as much as a mcmillan stock. I have decided to take the $200 loss and invest in a quality stock. I am going to have about $1400 in it by the time I'm done and that does not include optics. There is no way I will ever get that money out of it. I'd be lucky to get half.