The main problem with selling domains can be illustrated statistically, there are 110,000,000 .com, .net, .org, .info, and .biz domains. DNJournal reported about 25 sales over $5,000 in the last edition, let's assume another 25 go unreported making 50 in total to illustrate this point. That means you have a 1 in 2,000,000 chance each weak of selling a domain for more than $5,000. To put that into perspective 1 in 2,000,000 is the probability of a jet plane crashing each time it takes off.
The people right at the top of the pile have a far higher chance of selling their generic single word .coms for more than $5,000 which can only mean that people further down the chain have either a very very slim chance, equivalent to winning the lottery of selling a domain each week for more than $5,000. There are probably 1000's of domainers who hand regged domains in the last couple of years who have pretty much no chance, not even the chance of winning the lottery.
In terms of your question, how to deal with this, my strategy was to switch from .com to .pro because I could buy my way to being one of the top .pro domain registrants for a relatively modest investment. I got near the top when there were 6,500 .pro registrations and renewals cost $99. Now there are 40,000 registrations, renewals are $19.99, and restrictions have been eased, I'm near the top of a slightly bigger pile. Last week, there were 3 .pro sales reported so statistically, I had a 1 in 13,000 chance of being amongst the action. Assuming, my .pros are better quality than average, my chances of making a sale are higher. The proof of the pudding is the eating and although I didn't sell one of the 3 .pros sales that got reported, I sold Switch.pro the following week for $2,000, Switch.pro cost me $99 to register in 2007. $2,000 is nothing in the context of my $80,000 investment in .pro but in 2007, I wouldn't have been able to sell Switch.pro because the buyer was Japanese and at that point only professionals in the UK, US, Canada and France could register.
I'm not suggesting people go and invest in .pro domains, all I'm saying is if you didn't have the luxury of regging .coms in the mid to late 90s, you need to find a niche and be one of the key players in that niche. Secondly, if you can find a niche where there is potential for goal post shifting; in registration eligibility, pricing, registrar take up, mindset penetration, value appreciation etc, that will further improve your odds of selling.
The important thing is to know your market and offer value. My market is the extension savvy developer who wants a blockbuster single keyword for branding purposes but only wants to pay a small fraction of the .com, .net, or .org cost. I'm offering France.pro for sale at $4,500 on another NP thread with that logic in mind. France in any other gTLD would cost alot more than $4,500 so it's a cheap way to get the stellar keyword, a credible domain extension, and SEO geo-neutrality. Paris.pro sold for $2,888 in 2006 so even compared to similar keyword sales it offers good value, especially when you factor in the sixfold rise in .pro registrations since then.