If it were sold in an estate sale, where the auction companies tend to sell things to other dealers, the range box would probably fetch $100. I just did one of those for my father-in-law's household belongings after he passed. It's a pretty specialized item and may not even sell. Auction companies typically take 40%. They usually don't sell guns, (too much paperwork and hassle) but it's a broader category for a market than the range box. Still, it's a ML'er, (needing no FFL) so they might do it. Usually those folks don't know boo about that stuff. They might price it at $250. So your offer of $300 for everything is certainly in the ball park and a reasonable one. It's between the "sell it now and don't worry about it price", and the "retail find just the right guy some day down the road that wants to pay full price price". One price gets it sold today, and the other gets it sold maybe some day. Maybe.