Mystery Item - Solution

The answer is: House numbers!

Each digit costs $0.50. People always assume that the nubmer 1, 12 and 144 refer to the quantity of the items, which is what makes this puzzle hard.

To be fair, you must type out the numbers and not the words (ie: one, twelve, etc), in order not to be misleading.

This creative riddle was sent in by Samuel Fursey.