An addition to your summary: gummer claims that the grinder is worth $250 , and whines that picking it up requires him to veer from his normal path to the tune of $10 worth of gas. Conclusion: there's some other reason(s) that gummer hasn't picked it up. Reasonable speculation: gummy gave up his grinder for good reason a long time ago, and only brought up the subject because he's too stupid to keep his mouth shut about a bungled transaction.
Wayne