This thread is a great example of how not to do business. If I am a buyer & see someone asking for what they should sell a name for, I will think I have them right where I want them as they clearly do not have their own mind on value for their property.
Secondly if I get a ridiculous counter offer like that, I will just ignore it & chalk it up to a buyer being a jerk about it. Instead of feeling the person out & seeing what they would be willing to spend, you immediately convey to them that you don't take them seriously & they can piss off. Quite honestly the name is not a sure thing so you should take any offer you get seriously & go from there.
While your LLLL has good letters, it has no guarantee of being that money maker you want it to be. Most of the LLLL's I can guarantee will just end up trading hands for quite awhile. Banking on end users who might have companies to match letter combos is risky & a low % success rate at best.
I would seriously look into how you handle future offers or you could be screwing yourself over. If you don't want offers below a certain #, set a range so not to waste everyone's time.