I never visit a shop unless I have a Trawl Orb and I'm near the stairs. I use the orb to grab all the items (which triggers the angry Keckleon), quickly gather the items up and get up the stairs before they come. Although one usually seems to be planted like one space outside the room you used the Trawl Orb in, so you have to gather up those items and leave fast - the Kecleon are never far behind.