Theres so many scammers here in Sythe...
You just gotta be careful, NO matter how trusted you think they are, if you see one complaint, either don't trade with him/her or trade with caution.
Also, when they give out their PayPal, search it on Google to see if any scammer's account links with that PayPal, and their MSN, and ask to PM their MSN to you via Sythe.
I got scammed $80 in my few first months on Sythe, but pretty much never did scammed again (except from 2 pins, both from decently trusted pin-sellers), I am more cautious now.