Is it really necessary to move up to a $300K house?
I assume you live in Cincinnati. We live in a similarly-sized city not too far away, and here a $300K house is definitely very nice and/or large. We live in a $200K house (4 bedroom/3 bath, 2000 square feet, family of four) and we managed to find it in an area in our city where the kiddos would go to good schools. However, I know school districts in larger urban areas can have some confusing student assignment plans that don't always make sense, although some make it easier with "neighborhood schools."
My point is just that, even accounting for your current HOA, you would be moving up a LOT with your housing costs going with a $300K house. Not just the mortgage debt, which would more than double. But also there are so many more expenses when you own a free-standing home (yard crap, decoration, outside maintenance), insurance costs go up, and I'm guessing you or your wife would want to buy some new furniture (tell me if I'm wrong), even if it's just to "fill the house up." Hell, you might end up tripling your housing costs.
Do you really want to do that?