Prices for used bikes were stupid high 12 years ago too. For various reasons too. COVID certainly has not helped. If you are willing to pay 3500 bucks for a bike, you can get a decent new bike for that. Any old bike you pay that much for is already dated by more modern components that are on the new bikes.
The last used bike I bought was my Raleigh Comp and I paid less than half the asking price. If they won't come down, buy new.