I got the IMUSA from Wal-Mart for $21.47. It was out of stock, but I signed up for "Get In-Stock Alert" and got an e-mail about a week later -- free Site To Store shipping and it arrived in 3 days. http://www.walmart.com/ip/IMUSA-Tamale-and-Seafood-32-Quart-Steamer/13370045
The Vasconia is more expensive, but may be a better fit -- especially if you want to mount it on its own lid (raises the bottom of the pot slightly ABOVE the kettle, instead of sitting down inside it).
To see the lid under the Vasconia, see "Building a Mini Weber Smokey Mountain in Texas" on this site.
To see my workaround with the IMUSA pot, please see my post "IMUSA lid".