I'll readily and proudly admit to buying "used" items for more than 50% of retail. I've never bought a new Festool tool, and I have at least ten systainers that come immediately to mind. You don't buy used festool for less than 75%-80% of retail, because their retail price is strictly controlled (no bargains ever, except on reconditioned, and then only about 10% off), and they are usually well cared-for by OCD woodworkers. I buy Veritas/Lee Valley stuff used frequently, as well as Woodpeckers tools. Good luck finding those at 50%.
Conversely, I've bought a sliding table saw, 37" widebelt sander, vacuum veneer press system (with two 4x8 30mil Poly bags), 5hp tilting-spindle sliding-table shaper, shaper tooling, workbench, sanding table, Snap-On toolbox, Porter Cable 7518 routers (3), Equipto 8 drawer steel hardware cabinets (4 of those, with 400lbs per drawer capacity), 10' high Vestil steel cantilever racks (2), a 12x10 enclosed spray booth with explosion proof lighting and fire suppression system, and about a hundred other things that I'm too lazy to type out, at an average discount across all of them of ~85%. In other words, I paid 15% of retail for all of those items when their prices are aggregated together.
In real money, that's a five-figure sum that starts with a crooked number. So I have no problem paying more than 50% of retail for some items. That's the beauty of a market system; demand and scarcity set the price. See how quickly anything from Lie Nielsen, Blue Spruce or Gramercy Tool Works disappears on Sawmill Creek; if it's more than an hour, something is wrong, even if the price is 90% of retail. That's high demand.
Conversely, a 3phase spray booth that is dirty, that needs a new motor, that needs to be disassembled and transported in a large truck, and is almost as big as a small garage, is not nearly as attractive in the marketplace. That's why I was able to buy it at around $.05 on the dollar. A smart shopper can't just lock in to percentages, although it is good to have a rule of thumb. At least so far, luckily, I still have two of those, so I am flexible in deciding which hand makes the buy!
;-)
K