As written, prices are difficult to compare, all depending on need. I am in the situation to consider purchase of a printer for metal printing. Still am not sure about the solution to go for, but need will be for different metals, including titan, as some customers need very corrosion resistant items. Where do those printers start, price-wise ? Assume printable size/volume as ZPrinter 650 (254 x 381 x 203 mm). Using a 650 for prototyping.
Is it any second hand market ? Or is it only "by chance" you can find second hand printers ? I know several companies selling their equipment due to "wrong" investment, often too optimistic to what market are ready for.