Sounds like he's asking going market rate so I don't know why you would post that on his for sale thread. Let him ask market value. Hell, if he wants he can ask for more than the going market rate. I see lots of stuff listed here for more than I can buy it for elsewhere and, surprisingly, it often times sells.
You sell stuff on this forum too so try to think how you would feel if others posted the same thing to your thread. Not very helpful.