Gamivo is a challenge. They have lots of little tricks to make you pay more, but they're genuine. You sometimes have to scroll down to find the cheaper offers. The coupon code is usually only valid for the promoted more expensive offers. You need to untick the Customer Protection Program (CPP). Sometimes the cheaper price is sold out by the time I get to it and I walk away. I only buy if it's in my cart ready to go at the same price or within a few cents of the offer on G.G.Deals. After you select the payment option, the CPP fee is added again and needs to be removed. I use PayPal as a buffer to protect my card from all these key seller sites.
They're quick to resolve tickets even when I haven't used the CPP. I had one key that was a DLC, not the base game with DLC and they refunded it the same day. I had one key that was the wrong game and they refunded the same day and let me keep the wrong game. Both games were similar value so I think it was a genuine mistake from the vendor.