Capitalism dictates that a consumer spends his or her money to obtain the most value per dollar. If REI supplies this, than the consumer should purchase from REI. Buying from places because they're local only makes sense in terms of supporting business practices you agree with, reducing carbon emissions, have better prices, or you don't want to deal with shipping/travel time.

Capitalism is not a charity luncheon. The consumer is compelled to use his or her dollar in a way that will yield him or her the most benefit.

EDIT: Actually, I'm sure there are other reasons to buy local, but one of them is not "because it's local."