In fact, Justin's people tell us the Ashton house isn't even the frontrunner. Justin has now looked at 3 homes in Calabasas and he's looked at 2 of them more than once, but he's still not prepared to make an offer on anything and is continuing to look.
Two other points ... We're told Ashton is saying he wants to buy the house he's currently renting.
As for Justin, he's going on tour soon, so unless he finds the house he really wants ... he may rent for a while. The rich have such problems ...
In case you missed it, Justin called in to TMZ Live last week -- explaining his 8-figure real estate search ... and why Ashton's place is high on his list.