You can buy a used Crown Graphic with the stock lens for a few hundred, used film holders for $20-40, $50 for used tanks, etc. A frugal/patient person should be able to keep it to under $500 total - I went a bit over that because I bought a new Sekonic light meter. $2-3k is more if you're doing the enlarging yourself or shooting larger film like 8x10 where the costs rapidly grow out of control. However, if you're handy it can be a lot cheaper. Except for the lens and billows, which are relatively cheap on ebay, everything can be made out of relatively cheap material available at hardware store. The tricky part is leveling the lens and film planes.