This is the second part of the equation as I think the consensus is that GC will offer you 50 percent to about 60 percent or so for your guitar if it is in good to very good condition. Maybe a little less. Maybe a little more but generally that seems to be the range ... at least it has for me. But how does MF determine the price for the item itself? Let's say you bought the guitar new for $500. You will get an offer of 50-60 percent of what GC will sell it for. But what is that? Is it also 50 percent to 60 percent of the "new" price or some other factor? For argument's sake, let's say GC will resell that guitar for $300 or 60 percent of the new price (what you paid) but offer you 60 percent of that, so $180. So the "formula" would be Price to you = .6 times .6X (where X would be the price of the instrument when new.) So $500 new, $300 at GC's resale price, $180 into your pockets means you will be getting only .36 (little more than a third) of what you paid for it. .