I would say on Playerauctions alone you can see this. Also, League of Legends is releasing a mobile MOBA called Wild Rift, if you add this when it launches this would be great. You can see how the LoL market is here.
Rise of Kingdoms (ROK)(ROC) Accounts - Buy & Sell Securely At G2G.com
Rise of Kingdoms: Lost Crusade RoK Accounts
Also, this is just one game.
When it comes to a safety aspect this is very similar to other game sales. Sometimes depending on games you can register an account and not have it linked with your Google Play or Apple ID. This can be tracked as there are confirmation emails sent.
I personally think this will bring a lot of traffic here.