I think it's too much for a player to own 8 houses. If we set the limit that high, the rich players will just end up buying all the big and expensive properties, while the new, poorer players will have to settle for the cheap houses that nobody really wants to buy. So to avoid running out of big houses I recommend setting the limit to 5 houses per player, and no more than that. Also having some expensive properties on sale also allows the players to have something to grind for, since money is mostly useless in XGS these days.