If a person responding (or not) as they wish doesn't fit your lifestyle simply put a timeframe for a response in your initial inquiry. You don't even have to communicate that timeframe to the recipient of your message. If you don't have a response by your deadline, don't complete the transaction.

Example: Interested in your machine. If you'll take $5327.42 in Dogecoin, respond by 4pm and we'll make the deal. Have a great day.

Example2: I'll give you $250 cash. My offer expires on April 7th, 2018.

Example3-stealth deadline: Will you take $50? (impose your deadline here. If it passes, move on.)

Never could figure out some craigslist posters -- I call on an ad only to have the seller tell me it sold shortly after listing. Check the same category several days later and it is still posted.

My guess is what you are inquiring about has sold. I have also occasionally not replied to an inquiry if I get the impression the person inquiring could be difficult to deal with. Not saying that you (OP) is/are, but just sayin. . .

I know that I have posted games for sale in the past, taken the ad down after it being sold, and the ad was still there. I got tired of replying to so many questions so I just stopped answering them. I know it sounds kinda shitty....but we all have many things to do in our daily life. I have encountered other sellers with the same issue when asking about games for sale.

Worse is those replying to your for sale and never showing up like they say. If a seller doesn't respond they are just lazy and don't care and I move on.