how to report a scammer?

Send a support ticket with proof , provided that he actually has an account here, you can also report him to steam rep , and can you not charge back on paypal?

Doesn't usually PayPal keep records and you can pull back within allocated time if its a scam?

bump for edit thread

you are the reason steam now has draconian security measures for the market...

You have perfect trade feedback of +47. Did the person you were trading with have more/better? If not, then that was your first mistake. The person with less/worse feedback always goes first. That's a pretty solid custom around here.

Custom (vanity) URLs are also unique, but the users can change them. But since almost no browsers have a machine type monospace font in their address bar, it is easy to fool anyone with them, this is why trading with non-scammers tends to involve ID 64. And of course that's why many people use Enhanced Steam.

Don't call out. Edit the link out of your post. Scammer or not, calling out isn't allowed.