I think the gp is referring to coming in and buying a house for cash, something which is likely unaffordable for people who grew up in that community (because op says that pay scales are about 1/4 of what they are in tech metros).

Yes, so against migration. Migration always introduces these factors.

No, not necessarily.

Even poor migrants increase demand for housing unless they somehow can live in the meta verse or carry their own housing like a snail.