Say you have a 30k house, or any groddle meadow cottage, or even a bog house. But you have a lot of money, you're just short on houses. I think it would be cool (although it might ruin the street's aesthetics) if you could upgrade your house to the next level in the right neighborhood.
So sayin alakol, there are only 30k houses available, you'd buy the 30k house, and pay 20k to upgrade it to a 50k house.
If you're in Groddle Meadow and say there are no 15k houses left, you could do the same thing.
I know house upgrades are going to come out in like 8 weeks, but I thought that his *possibly* could be a somewhat feasible implementation.