same problem on ver .10 running a sandbox game.
I have 23 prisoners when i go thru the quick sell box 138 denars offered 92 denars received however if i select choose prisoners to ransom and select all i will get full 138 denars. I have roguery of 107 with all four top perks picked. This has been a constant issue at first i thought cause i didnt have the 20% better deals it was that but even after am still not receiving full offered prices thru quick click.