My idea of a 'respectable cost' would be a price based off the 'new' price at time of purchase, adding in 'new' cost of any enhancements improving upon original design or ability that may have been added then subtracting depreciation and/or normal wear/tear credit based on the age of original equipment deployment date.
So say a item,
hypothetically, was originally purchased for $200.00 in 2015. Another $75.00 in enhancements were added... total now $275.00. Item is now 6 years old and most likely is no longer in production in it's original form and availability of replacement parts are scarce if at all available. Unit has been in 24/7/365 use. Allowing for a depreciation of used item I would assume no more than a max cost of roughly $175 with a written guarantee that the unit will work upon arrival in it's present, unaltered state as shipped.
I also would not pay the same money for a used item which equates to being the same price point of a newer up to date model of same.
