I bought the plans for this off of eBay. It took me about 2 hours to cut all the parts, and another 3 hours to weld and assemble.
Decided to try it out while I warmed up the bike.
About 200 bucks. To save money, you have to buy in sticks and sheets, so it's cheaper to build 2 of them, which I did. Just went in half on materials with a friend.
I think you can get one at HF for about 400 or maybe cheaper, but I looked at one of those and they are CHEAP, plus the jack is hand or foot pump only. Everything on mine except for the deck is made from 3/16" wall steel. The deck is 1/8" tread plate. Probably overkill, but a bagger weighs 800 plus.