It is always advisable to be wary when purchasing second hand card machines from eBay or other such auction sites. The reason being that the hardware may still be under contract elsewhere meaning you may be liable for any remaining charges. You may struggle to change the merchant account numbers across on the card machine, and some companies will charge a fixed fee for the privilege. Before you know it, the second hand card machine that looked such an enticing deal may suddenly appear not such a good deal after all. If you opt for a second hand card machine, use a trusted hardware supplier or use a manufacturer directly.