Are four letter domains worth that much right now? Also, what if they have a number in them like LNLL?
4 letter domains are only worth alot of they are actually a word or an acronym which is not abstract. For instance, I bought the domain lewi.com and no one is interested for reasons stated above. If they have a number, thats probably worse unless its not some random combination. I'd stick to 3 letter domains. I had one that was 2 letters and 1 number and it sold pretty well.