"Good, because I've already signed the lease," he says, perhaps somewhat cheekily, and then calls into the adjacent room, "Back in a moment, gentlemen." There's no response, but Erik doesn't care. Those two gents are cordially invited to suck it, honestly—their distaste for his (their) mere existence is nothing new in his world, and he's not about to let the same old hypocrisy tarnish his mood.
They'll change their minds soon enough, anyway.

"The offer was not going to last, so I leapt on it while I could. Shall we?" Walk, he means, to get away from the likelihood of eavesdropping.