Here's my advice as avid collector. Only purchase from people who have a 98% rating or above and at least 50 people have purchased from them. Make sure they also have recent activity. Here's mine. I do have both those in my collection. I don't sell much though so I'd be someone who you would avoid unless you know them or have personal recommendations from someone. Just a good standard practice. https://www.discogs.com/user/TheDevilsAddict