How many times Artificer's Chisel can be used?
A new Artificer's Chisel or Artificer's Hammer comes with 5 charges/uses. As such, make sure to check how many charges one has before buying it from the Marketplace. When there's no indication of the number of uses left in the item's description when mousing over it, it means there's only one left. As you might expect, many evil people will consume 4 of them and then put it up with only one charge left and try to sell it at or around full price.
Conversely, if you don't need that many charges, you might find a good price for the ones that are partly consumed.
The best way to weed through the listings is to enable the "Include descriptions in search" checkbox under the search bar and include the number of charges you want to search for. For example, "appid:570 artificer 5" to only see listings for the ones that have all 5 of their charges.