Funge, verb: niche lay-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.