Nobody is attacking or questioning you so please don't take it that way. But flip this around if you are buying. Would you spend $110 on the ball and hope it is real or spend $175-$200 to get one that is PSA/DNA and KNOW is real (or at least can be 95% sure as even those guys make mistakes)
And past that, if you buy something and send it in and it isn't real, then what? If you buy from a reputable dealer they are going to quickly refund your money and probably give you something else for your trouble (or at least that is how we would handle it) . If you buy it or trade from it and it comes from the kid down the street, then what? You are going to have to chase and chase and file police reports and hope they will do something to help you because going to small claims court on something halfway across the country is not normally a viable option.
I have bought and sold several UDA Griffey items and a couple of autographed Gartlan figurines so I have seen a few different Griffey autographs and yours looks good but still, most of the fakes DO look good.
That is why I suggested if you believe it is real to spend the money to get it authenticated. You will get MORE than what the authentication costs back when you sell it. And if it isn't real, you don't risk your own reputation by selling someone a fake and you can start the process of going after whomever you got it from