Hardware for Pawn Shops
There may be 2 reasons to buy hardware from the software provider: 1) To be sure you get the correct hardware, and 2) convenience.
The name & model # of a hardware piece "is what it is". That is all that is needed from the software provider. Search Google for the hardware make and model # and compare available prices (cables included).
You gain nothing by purchasing hardware from a software vendor. The warranties and guarantees are the same because they are provided by the manufacturer. Shipping time will be the same (or longer if adding an unnecessary middle man also adds delays). Just be sure to seek support for the hardware from the vendor who sells it to you.