are we are own worst enemies?

You pose an interesting question. Audiogon is a market that consists of buyers and sellers. Economic theory on free markets states that at some point price equilibrium is met. It is set at point where supply and demand meet. When there is a greater demand than supply then prices rise. When there is a greater supply than demand then prices fall. It is no different in this market. We would demand higher prices for our equipment if we could get it. I would argue that the market has determined acceptable prices based on what we will pay. Technological advances in digital technology has not helped those of us who have digital items for sale either.

Go to eBay and sell your stuff for more than you should be allowed to. If you want 65% for near mint, then ask 65% and be patient, a person who really wants it will appear eventually. 50% is for demo traders. At 50% people can trade stuff, try it out, and if not to their taste can resell for 50%.

You make a sound point (pun intended) -- I also happen to agree that it is not necessary to automatically price your used gear at 50% below retail. The audio "blue book" often lists audio gear at about half of MSRP, but like the "blue book" price for automobiles, the price should be a starting point based on some common standards. Like cars that have low mileage and are in top condition, nearly new, non-obsolescent audio gear (such as speakers, analog preamps, power amps, tonearms, etc.) should retain its value better over time. Equipment that is subject to frequent technical change (such as digital equipment, surround processors, etc.), or subject to wear (such as phono cartridges) will lose their value more quickly.

When I price my equipment for sale, I try to decide what I think is a fair value for both me and the buyer. I take into consideration factors such as age and condition of the item, the price I originally paid (I set the price based on what I paid, not the MSRP), whether the item has a transferrable warranty (such as Bryston equipment), etc.

Ultimately, the buyer and seller must both agree on the perceived fairness of the price, and that perceived "fair value" may be 50% of MSRP, and it may be more.