Why is this not the solution?

[Nepentha]

People will outbid everyone else just to resell the houses and make a profit, like the way houses were before the timer was added in but with extra steps

Interesting, but I dunno. Say a small house goes up for 3 mill placard base price. People bid on it until finally no one wants to bid higher. Say it sold finally for 300 million. How would you then resell that for more when people aren't interested in paying that much to begin with since that was the highest bid?