+2, although I wasn't aware of Denny's site until after I started brewing from grain.
OP, keep in mind that in the long run, "cheaping out" on equipment can be more expensive, when you have to replace something that works, but not as well as you'd hoped for.
That said, when I built my first mash tun, I found an Igloo cooler on clearance at Wally World for about $15. Another $10 in parts, and I had a really functional mash tun that I still use today.
Of course, I just HAD to build a version 2 mash tun. The MashTun1.0 still works great, though.