Yes timer, no to the length and put a random timer on relocations

[Gallus]

Put up some kind of glowing light around the plot or a flag or something to indicate the timer is up. That will allow people to not have to click every few seconds and hope that they are blessed by RNG.

This solves nothing, as the same millisecond the house is available for purchase one of the 6 players spamming the placard will instabuy it. You won't even get the chance to see your suggested flag.