Sounds like you made the right moves asking to come see them and proposing the time. I'm not a pinball power seller by any means, I've sold maybe 5 vids and 5 or 6 pins in my time in the hobby, but after the first 2 or 3 you can smell the tire kickers, picture collectors, and window shoppers in the first 2 minutes of the conversation. I don't take it personally but I think doing what you did is the best way to eliminate the nonsense. Ask direct actionable questions, get a deposit if it gets that far, and put accountability on them.

I've never shipped a game so I've really only had local sales, but once someone starts to ask a lot of tire kicking questions or you can tell they are just window shopping you just quickly pivot to something like "well I have X other messages so what time would you like to come see the game". Usually they either make an excuse about checking the schedule and you never hear from them again or they come over and buy the game. I don't know if it helps, but I've taken to putting something like "please ask the wife, secure a truck, check with your moving buddy, go to the bank, etc. before contacting me". Who knows if it actually helps but it makes me feel better

I was selling a multicade last year and talking with someone who was "very excited" because it "would make the perfect Christmas gift for the kids". I wanted to know when they would be over to look at the game, and I get "can you send me 150 pictures of X, Y and Z". I replied sure, but I'll need a $5.00 PayPal deposit. 2 hours later "the wife said no".

Most people like the idea of spending money, but not actually spending money.