What's the best way to put a dollar value to firearms? I'm thinking looking around gun broker to get an idea of similar rifles, pistols and shotguns to get a ball park price.
Gunbroker is good for this, just search the completed auctions so you can get a sense of what the guns have sold for. Also a big gun show could work too or maybe go to a library or book store and look through the latest gun value guides.
And unfortunately it's much harder to get your money back on "customized" guns, or any other item. What suits one's fancy, may not suit everyone else. Like mentioned above, finding a sold GunBroker item as close as a match to yours is the best way.