Question on this proposition: Would the used items still be ‘level locked’ like the original? That is, if you have to be Level 20 to buy bike X, and you later wanted to sell it, would the buyer also have to be Level 20?
Also, at least from my perspective, drops accumulate REALLY quickly. So why would someone buy something used, and slightly slower (per the OP), instead of just waiting a little longer and getting a new one?
The issue I see with the present set up is that you run out of things worth purchasing reasonably quickly (presuming the purchase is performance-based, that is) because the testing for what is the ‘best’ for different terrains/surfaces has been done.
Personally, I am still in favor of the purchased items each having their own ‘health’ and needing to spend Drops for maintenance on a regular basis. For example: tires to be replaced, chains to be replaced, and even though kits aren’t through the drop shop (at least not yet), Lord knows we can see through those bibs you’ve been wearing for the last 15,000 miles!!!