I prefer Pound Shops. Great fun can be had by brousing around the aisles and tormenting the dimwitted assistant thus:
"How much is this?"
"A pound sir"
"Oh okay. Hmmm. So how much is that?"
"A pound sir, everything is a pound"
"Right. And how much is this thing?"
"A pound! Everything in the shop is a pound!! ONE POUND! Get it??"
"Oh right, I see. Urm, how many of these do you get for a pound?".... etc.