Selling is primarily about price. Over the last 5 years I was able to sell all of my Z,N,HO,S, & unwanted O gauge trains either here, at a show, or on the big auction site within less than a week of listing them by following one of two simple rules:
1) Price it fairly which is usually 10% - 20% less than comparable sold prices I can find listed elsewhere. This rule I apply to only to hard to find pristine items.
2) Otherwise I price it at a price I would be willing to pay for it either at a show or online (including shipping); and FYI, I am notoriously frugal, or as a dear old Scotch friend used to say, "It's easier to save than it is to earn". Within the last month I sold all my standard gauge track & switches at a show before i was able to get it all displayed - it was priced right.
After all, remember we are selling it because we no longer want or have a use for it. Trains are a hobby, ie expenditure and not an investment. If we golf as a hobby and a downpour makes the course unplayable after the 15th hole do we ask for our green fees back? If we ski as a hobby and sprain an ankle midday and can no longer ski the remainder of the day, do we ask for a refund on our lift ticket?