I think you are going to be suprised at how quickly the prices of some items are going to TANK with the patch because of the exact reasons you states, people will start trying to do nothing "But" get money materia will flood the market harder than it ever has, tome items will be on the market (Hell it's less than 10k a peice on some servers allready) the effective money making potential of dungeons drops the more people do it for money.
So yes the smallest FC's will actually have a very hard/long time getting money. Hell my FC is 2 people we had hoped to buy the smallest plot after maybe a month or two of scratching up cash I had a mill saved up in a rather rough market (Aegis has pretty low prices on pretty much everything) the flooding of items that are allready flooding legacy markets will become even more severe rock bottoming the prices even faster.