Check out these prices at restaurant supply house for aluminum pots. I saw this link from someone else on another thread.
Cookware:Stock Pots
I am getting ready to buy a pot myself. Does anyone see any problems with the 15 gallon pot for 5 gallon batches? I plan to start with 5 gallon batches but i see myself eventually doing 10 gallons. I also wonder if the medium weight pot is enough or if it is worth spending the extra money on the heavier, 6mm pot.
* Do not buy from the above site! They do not have internet security and do not reply to emails!