Ten Tec 6'n2 comes to mind. But, they are discontinued and expensive used. You might want to get a couple of Ten Tec transverters (discontinued, used) and put a small amp on the 8 watts or so that they put out. About $125 each, so maybe $250?
I don't think you are going to find an inexpensive 6 and 2 meter only rig. Hell, if they existed, I'd have one.
Seriously, the transverters work quite well, I have three of them. Models exist to go from 20m or 10m to either 6m or 2m. One of the units I have goes from 2m to 6m, I'm not sure if they made one to go from 6m to 2m.