Actually, the Aimpoint isn't that much more. Having to buy an appropriate mount is what makes it more expensive as a whole.
If the budget is a strict $350, probably EOtech. I like those, but Aimpoint is superior.
Me personally, I'd rather just put that sweet XS tritium front post on there with a large rear aperture. Fast. Anything at CQB range is deadmeat. We're talking point and shoot range, but you still prefer to aim type scenario. Dots are nice no doubt, but don't believe they are mandatory for effectiveness.