If you're interested in a real pot for brewing - consider something bigger that would allow you to do full boils with 7.5 or 8 gallon capacity. Also - check out the sizes of his wort chiller & the thickness of the stainless. If you want to spend the minimal amount possible - go for it - but consider you can buy better equipment for not much more $ and have some room if you decide to upgrade into full boils.
I actually have, I believe, a 7.5 gallon pot at home that I currently use. I've only brewed three extract kits thus far, and just built a mash tun to start all grain brewing. I figured I would get another pot or two to make it easier.....you know, having a pot to catch the wort, and a pot to boil water in to add during the lauter phase. I paid fifty bucks for my pot, and $18 sounded like a great deal as a spare. I also heard that you tend to end up with more wort than you shoot for because of efficiency issues and whatnot. Gott catch it somewhere!
I actually asked him if he had larger pots, in the 10-15 gallon range, but he said he hasn't been able to find anything of that size at a reasonable price. A full keg (possibly a second) has recently come into my posession. I may turn the second one, if it is stainless, into a pot.