I stay away from used equipment like the plague. The only things that happen from used equipment is heartache and pain. If I observe operations of said unit, do the takeout myself, seal everything properly, then I may consider installing it at another place. But when you think about it,,, the customer doesn't care that it was used, they just know that you put it in and three weeks later it took a crap on em. Your name goes in the gutter and you end up married to that unit.