Any of you previous 1st gen Tundra Owners?

Let me say first, that I do really like my Tacoma, and this may not be the place to ask, but I've been thinking about getting something with more cab room and a little more carrying capacity.

So, first off, I've been an owner of an 05 Tacoma TRD 4x4 AC for about 1.5yrs. I love the truck. I have 265/75/16 Terra Grapplers on it, and still get 17mpg city/highway during the winter, and about 19mpg combined in the summer. I don't like the size, though. Well, I do, and I don't. I find that there's times I want more cab room to fit people in the back, and I would like a bigger (deeper) bed. I have my truck paid for, and don't want to enter into payments again, so I've been looking at 1st gen Tundras. Now, I know guys get mixed results with the mpg, and I know I'm going to take a hit mpg wise, but if it's severe (like 12mpg avgs), then it's probably not worth it. Granted, I will be driving less finally because my fiance and I will be married soon and she will be done with school (driving 1.5hrs out and back every weekend causes me to blow through gas quite a bit), and my commute will turn into almost 95% highway.

Anyways, I found an 06 Tundra Double Cab 4wd with 94,000 miles (my Tacoma has 75K). I know the 1st gen tundras can easily make it to 200K, so that doesn't worry me. The dealership wants $12,500 for it. The tires are new, but there's no maintenance records (haven't had a chance to go look at it, as it's a decent ways away), and it was a smoker who owned it (big downer).

I was thinking maybe offering $11,300?

However, maybe it's not worth it. I'm sure I can sell my Tacoma for at around $16K (it's loaded), so I would actually walk away with a little extra cash, and if the mpgs are close (2-3mpg), it would take a long time for the cost savings of the gas to catch up with the difference.

Thoughts?