Good as long as you don't have to deal with the support.
For anyone who uses OnlineKeyStore I recommend to use another key selling service. Due a fault on their side (sending an already used key to me) it came to a discussion with the support. But instead of solving this issue fast and satisfactory the support didn't even manage to give me a specific time for a TeamViewer session the wanted. Only a timeline within the support didn't connect although I sent them the ID and Password. They argued that I want to cut the line against other customers but I only wanted to get a note when the support is ready for a TeamViewer session. They didn't refund either. I would report to a lawyer but the small amount is not worth it. Anyway in my opinion this smells like a fraud. OKS is only ok if there is no issue. As soon you have to deal with their support it is terrible. I strongly recommend not to use this key seller.