Look on gunbroker.com and search for browning citori 20ga. You will find several with a buy it now price around $1,200. with various dings. Find the one closest to your brother's and you have a good comparison to current asking prices. Unless his is a higher grade the offer may not be too far away. As to the "friend" damaging the gun and not reporting or fixing it properly, I think your brother learned how "good" a friend he really is. Maybe they can come to an agreement. Good luck!