Are you SURE you know what you are talking about? Each domain worths at least its registration fee. I guess a 4 letters .com domain names worth is at least $10, no matter how bad it might be..
I must have missed registrars handing out all LLNN .com's for $0. Yes, it certainly shouldn't hold the same value of an LLLL .com, but to say it is entirely without value is asinine. I for one would prefer, for example, news247.com over newstwentyfourseven.com any day.
I would agree with @verybad. If the domain has two letters and two numbers, it has zero (0) value. But if all the 4 are letters then the price of the domain would depend on the combination of the letters that make up the name. What you can do is try to check Sedo for sales of similar domain names and this might help you evaluate the worth of your domain.
Two numbers and two letters are NOT LLLL .com $0, unless any meaning, not even reg fee. Other than that, you should include the domain you want to appraise, it's a rule, isn't it?
If it has a few hits on the Acronym finder - check acronymfinder(dot)com - it can be worth TONS to and end user. If not, random LLNN good luck. And agree with above, plz disclose domain name for better appraisal judgment as age, development, etc. are definitely a deciding factor.
It may be $10 to 10k.Just try to find out that company who really need it.They you can buy it for $10k+