Hi, I'd like to sell this piece of equipment for $40
Hi, was this painted black or was it origianlly black?
Painted black
And I can see there are a few scratches on this side, how about hte other side and the top?
Everything else is good to go
Ok. I was wondering if you would accept $24 for it
Whoa, that's way too low. I can go down to $30
I don't know those scratches look pretty big, so I am going to have to repaint it and that's time and money.
Submit an offer and I'll accept or reject
Well I would like to know if you will come down to $24?
Submit an offer and I'll either accept or reject, but choose wisely otherwise we both lose out on real money
so why not work out an offer here and now to ensure we are both paid? 
Because time is of the essence
Agreed. So you agree to $24?