Gun sales tend to drop off right at this time. People have to pay taxes, the economy weighs heavy on people's minds, few people have their refund checks if they're getting any, and most people pay their major bills (like mortgage or child support) at the end of the month. There's a multitude of reasons, but as SS109 says, I go to the show to get a deal. I find them all the time, so it's worth going even if I don't find any that time.
Usually when someone asks your price, you reply, and say "it's worth it but I don't have the cash, etc" they're just looking for an exit out. It's when somebody actually gives you an offer that they're serious. Also take into consideration that not everyone is interested in a 24" barrel, but may be intrigued to give it a go if they could get one cheap enough. Anything non-standard appeals to a smaller market than a standard model. All you can do is exactly what you did. Walk around with it and try to sell it. Your odds were higher at the gunshow that you'd find someone interested in it, and higher that you'd have alot of tire kickers. Larger population, so you'll have a higher prospect to buyer ratio.
As for the dealers, it's nothing personal. It's all about how low you buy, not how high you sell that makes you money.
I've noticed the for sale board is pretty slow lately as well. Have you tried over there? Good luck selling it.
Ross