I bought a new one from lowe's about 2 years ago because the thermostat on the old one went south and it was one of those anti-tamper deals, hard to get in there and fix it and prolly couldn't have sourced parts.
I paid around $500 for the new one IIRC. It's got a whirlpool sticker on it but who knows who actually made it for them. It's 40 gallon and works just fine.
Here's the deal on gas water heaters (or "hot water heaters" for the anal nannies), they usually don't go bad until the zink anode gets eaten away.
I've heard rumors you can replace that anode.
It screws into the top of the tank.
So buy the cheaper "hot water heater" with the lower warranty, and after about 5 years replace the anode and the thing should last a lot longer than you'll need it to.
Or, you could spend an extra $1000 to save $400 in gas bills over the life of it
