FB Marketplace isn't too bad if you have the right expectations and do a couple of things...

1. Just add a note at the end of every listing stating "Automated 'is this available' type messages will be ignored and deleted", and then follow through with it. The problem is that on every listing, FB has a pre-populated "is this available" message with a "send" button ready to go. The "send" button is conveniently on the right side of the page, and since most people are right-handed, it's easy to accidentally hit that with your thumb while scrolling. I'd guess a majority of the people that you get that message from don't even realize you sent it. But I put that disclaimer there so that anyone that is intentionally messaging me knows to send an actual message if they expect a response.

2. "Local only - no shipping". If I get a message from someone that isn't in my area, I completely ignore and delete it unless they specifically say they'll be in my area or something to that effect. Do I potentially miss out on a sale here or there? Possibly, but I'll just move on to the next person.

3. Choose a meet-up spot that is convenient to YOU (as a seller). If the buyer is serious, they'll meet you...if not, you didn't go way out of your way or waste a lot of time. As a buyer, I haven't ever really had any issue showing up to buy something and the [/i]seller[/i] standing me up.