Amazon Prime: Marked Up?

I used to think I was so shrewd and sneaky by shopping at Home Depot with my smartphone in hand, scanning barcodes and finding lower prices on But during the past few trips I’ve noticed Home Depot has the lowest prices!

Sure, free shipping for Prime, but is Prime stuff marked up?

UPDATE: “prime” was misplaced, above. Really I was just wondering if Amazon prices are marked up to cover shipping costs. Prime needn’t enter into this.