Refurbished miners could be a great bargain if you get a diamond in the rough with no issues but that is playing a dangerous game if there is no warranty attached to them. Depending on the price and time to get to you it may pay itself off quickly but if it breaks it could quickly become a paperweight or something that ends u costing what a new unit would plus the downtime to ship it back for repairs.  Would love to hear feedback as well from anyone who bought one.