"Beginner to professional" Picassos find a "wide range of brushes, canvases, paints" and other "supplies for all art forms" at these "full-service" stores; staffers "try to help you" whether you're there for "custom framing" or prepping for a project, leading many to muse "why order online when you can go see what you want?"; P.S. insiders note that the "reasonable" prices get even more so if...