regardless if the domain is worth a certain price or not, I would not bother justifying your price.
I assume this is through SEDO.
the most I answer is: "this is what I would consider selling for"
the 3 letters are good. So, your reply make sense, and from there its a hit or miss situation.
the combo has decent acronyms as well, and since one has to assume it is an end user at the other side, your reply was a good one.