don't know about what your selling but a basic rule of thumb on ebay is if you list a buy it now with a best offer option, your basically telling people that you will take less than your buy it now option, so of course they are going to low ball you.
now if you list it starting at a low price with no reserve it will force people to start bidding and usually get more people to put it on their watch list and eventually bid, and more often than not I make out better than what I would have set as a buy it now price by doing it that way. of course listing with no reserve and a low price will make all these people that are low balling you in the first place ask you for a buy it now because they don't want other people to push up the price, yet they don't want to let something get away from them at a price they know is really half way decent.
I should have been a therapist.