Funge, verb: nichelay-economics term meaning "trade off" or "can be traded off". Invented verb form of "fungible", meaning economically interchangeable.
Usage: "X funges against Y" or "I'd funge X against Y."
The example indicates that they'd take a big, somewhat noisy apartment if it was moderately cheap.
Indicates that you care about a property, but correspondingly about another property, so that some increase in one is worth some decrease in the other, in a somewhat linear fashion.
"I want a bigapartment, but that funges against price and noise, to a point."