I've bought quite some vinyls on Discogs.
On the positive side: you can find almost anything worldwide.
The payment system is really bad. There is often only Paypal and sometimes wire transfer but if your money doesn't reach the seller in time you automatically get negative buyer feedback, even if you tell the seller that the money is on it's way with a payment screenshot.
It happened to me while I was waiting for the seller's answers.
That seller also had free shipping until I submitted my cart, then he added shipping costs.
The seller also offered retrieval but when asked about this he did not reply.
I had this experience with seller Dr_groovy who didn't answer my questions and after wasting a lot of time not answering I wired the money anyway and informed him with a payment screenshot.
Even though he knew the money was wired he still gave me negative buyer feedback anyway, when he got the money he sent the items but there was no way of giving negative feedback to the seller.
This seller had 99,5 % or so positive reviews but no wonder because negative feedback could not even be submitted.
I sent a couple of emails to Discogs but deafenig silence from their side. Nothing. No answer at all.
I even found that Discogs somehow deleted my messages to and from that seller Dr_groovy. I had to check my email account to retrieve the emails.
I sometimes buy from Groovesland Berlin and except for the stress I get from the payment system that seems to work out.