Yeah, a Tundra is a 1/2 ton truck and does not run E tires. Different animal.
I try to save $$ where I can but don't use cheap tires on anything. It gets tricky because sometimes off-brand tires are good tires just rebranded but not always. In the last year, I've bought a set of Michelins for one truck and a set of General A/Ts for another, both good tires. I got a good deal on both, the Michelins were on sale on Tirerack and the Generals I get a good price locally on.
I can get the Generals for you installed for $600 out-the-door in 265/75 16s 10-ply in Hollywood, let me know.