i have a 2006 crew cab GMC sierra Z-71 p/u and i get about 20mpg. This is after a cool air intake, exhaust, and a programmer. everything else is stock. you could get a used one for 20K or less easy. i would look for something in the southwest if possible so it won't be rusty already. My truck has room for my wife and I with two adults in the back seat including a car seat for the kid. we could fit someone in the middle up front too if needed. it is comfortable for five and has room for six if needed. Also, I just put stuff in the back seat if i need it locked up.there are also locking cargo covers for the bed that rool away for hauling stuff. just a few ideas for you. good luck!