Going back to the original point of this thread, why would you send something if you haven't received payment?
The where in the OP did he say he'd sent it?
I once showed interest in a car in Essex on Gumtree. Caught a train down there, met the dude at the train station, he took me for a drive and offered me the wheel. Before driving I wanted to have a look at the car and said so.
It had HGF, two punctures (I could literally hear the tires deflating as I stood next to them) and the rear discs were spray painted, and still had the wet pain on them.
When I said I'd think about it, he hopped in and drove off, leaving me stranded in the middle of bloody nowhere. It was a long walk but a lesson well learned.
I sold a Phone on ebay once.
The Buyer used an Obvious stolen Paypal to pay (His Ebay was registered to wales, The paypal account to scotland).
I managed to call the Paypal account owner, who then told me that indeed they didnt buy anything from me. I then asked them not to do anything for 3 days whilst i investigate and they agreed.
I then sent a box with a stone in to the E-bay Registered Postal address. (used to be that you had to send to Paypal address, But they changed it a few weeks before)
It then showed Delivered with RMSD.
Then the Paypal owner put an non autharised Claim in and got their money back, which caused ebay to pull my funds from me.
I then complained and said that i had infact posted the item and Myself and the Paypal owner are a victim of fraud.
Paypal gave the money back to me and left it at that as i had proof of delivery.
SO Scammer 0 Me 1 and i had £350 and the phone still
Now then, To anyone who will say what i did was wrong... Ebay has given my money back to many buyers in the past without any real reason. And i have been ripped off. That £350 wouldn't cover it.
I only ever sell items for Buy-it-now and require payment immediately. This stops the OP's issue completely
Whilst scammers and time wasters are a lot rarer on the MM, it isn't exactly a seller's paradise. Expect to sell things for less money than you'd get on ebay; after all you're selling to a much more limited (and knowledgeable) userbase.
MM in a nutshell:
Seller - XYZ2300 CPU: does 7.5GHz stable on air. Paid £400 for it. Looking for £300.
Poster 2 - willl you take £50?
MM in a nutshell:
Seller - XYZ2300 CPU: does 7.5GHz stable on air. Paid £400 for it. Looking for £300.
Poster 2 - willl you take £50?