Red Velvet Cupcake

In the center of the cupcake shop, bathed by a gentle light, sat a glass pedestal.
There, in the light, a cupcake.
A red velvet chocolate cupcake.
The greatest… ever!
I approached it, guessed at its weight, filled a small giftbag with mini-cupcakes about the same weight as the red velvet cupcake, swapped the bag for it.
I waited.
Nothing.
Walking to the door, I expected a low rumble and blow darts and a spiked pit…
Oh, and a gigantic boulder to chase me.
Instead, the store owner hit a switch and locked the door.
“You gonna pay for that?”