I don't think it matters. It's a supply and demand thing. I'm in seattle, and I almost think bikes are more expensive here then in say SF or LA, because they're just aren't that many for sale.
I live in MN and when I was looking I found it was a little cheaper to go south to find a bike. Especially into more populated areas. However, when weighing the savings against the cost of getting the bike back to MN it didn't come out to be much of a difference.
Has anybody found a cheep reliable company to rent a trailer from that can carry a bike. I've seen a couple bikes in portland (I'm in seattle) that I would have gotten if I had money at the time, but being a brand new MSF graduate I'm not exactly up to riding the 220 freeway miles between portland and seattle. I know you can get trailers from UHAUL but I was curious if people have found a better way to move a bike long distances with out riding it.