It's entirely possible that, for the most part, land ownership is not an economic issue for wizards. They are a very small population with no reliance on infrastructure and with easy, accessible and instant transportation from the FlooNetwork and apperation. They don't have pay utility bills either.

I'm willing to bet the only properties that change hands with meaningful frequency are shops in Hogsmead and Diagon Alley. Some folks rent rooms in these places when they are young and career-driven, but when they settle down to raise a family, if they haven't got a property to inherent, they just zip out to some picturesque chunk of rural Britain, get their friends together or hire some specialists to magically assemble a house, and then the ministry stops by to register the place and hook the fireplace up to the Floo Network for a fee.

The vast majority of wizards we see in canon live rurally. Bill and Fleur get set up with a little seaside cottage when they get married and no mention is ever made of cost. The only wizarding house that isn't rural which we know of is Number 12, Grimmauld Place, which was probably straight-up stolen from it's muggle owners in the 19th century and hidden.

Of course, if some muggles show up to ask why their land suddenly has a cozy little house on it that wasn't there yesterday, you bust out the memory charms and suddenly it's been your property all along, sorry for the trouble neighbor.