Ehn... they pull some of the gold flow back in via popping up lounges, though, which drain tax money out of the system. Your best bet for extra buildings would be, hrm. Do wizard towers count? Don't think they have a multiplier. Inns are fairly cheap, too, and generate gold besides. Dunno if statues'd do it...
Point being, going for gold I probably wouldn't make more than one bungalow, m'self. One's good/incredible, but they've got diminishing returns on 'em. One thing you might be able to do with the expansion is hire/dismiss embassy heros until you're full up on elves that way. Elven heroes, no extra lounges. A match made in incredibly wasteful heaven. Though now I'm wondering if you could, like, game it. Make a bungalow, and an outpost, hire a couple of elves, destroy the bungalow, wait for the elves to move into the outpost, rebuild the bungalow and repeat until outpost full. Eight elves, one bungalow, (hopefully) one lounge.
'Course, that's all moot when gnomes are the best of the non-humans anyway