Is it true that getting several pre-approvals within a short time span (30-45 days) doesn't hurt your credit more than 1 pre-approval? And how much do rates vary between different bancks, credit unions, etc? I've seen some people recommend getting one pre-approval, then when you find a house you want, you can get quotes from other banks/CUs. Is there a Mustachian-preferred way to rate-shop?
A little background: We currently rent a SF. We're in the early stages of our search for a duplex that we plan to live in one half of while renting out the other half. We'd much prefer a side-by-side duplex over an over-under, but over-unders are far more common in the areas we're considering. So it could be a while before the right one comes up for sale. So, to that point, how long are pre-approvals usually good for?