Usually, people go for either all letters or all # domain names. They just worth more, alot more... Unless you're talking about names like 7am, 12am, etc... Then we're talking serious cash.
Names you thought up yourself, should reflect words, letters commonly used by people. You shouldn't just mix letters and numbers together and expect people to understand what it is. Moreover, if the domain name doesn't have traffic in it at all, then it pretty much worth nearly nothing.
I'd say it's worth what you pay for... There are two ways to make a sizable profit. 1, devleop a Website out of it and generate a substantial amount of traffic in it per month... 2, in the long run, hope someone will buy it from you.