I wonder how much the fees charged by Ebay, Reverb, etc have contributed to the prices of used gear.     You have a guitar that is worth $1500.  Reverb puts about 8% on it,  if you use Paypal,  there's another 3.5%.    Someone is now asking $1670 just to break even.   Then you pay 5-7% sales tax on it, and that 1500 guitar is now costing somebody about $250 more than it's worth.   You decide to flip it, since you don't "bond" with it,  so the cycle begins again.   By now, that $1500 gets listed for about $2K, just to cover the fees you've spent and are going to spend.  Two flips, and the guitar costs more than a new one.   Nobody is will to take  a loss on used equipment these days.   The next guy sees that the same guitar just got listed for $2K, so he lists his for $2100. 
I remember reading classified ads in the newspaper.  It cost about $2 for 3 day listing.   That's how I found my Jaguar back in the late 60s.   It cost $200 used vs a new one being $300+.
I blame Reverb and Paypal for inflation!    Maybe we can get congress to look into this!