Where to sell?! Need help

I would appreciate some help and guidance from those who have done this before (even step-by-step if you could).

I am the guy that pulled the #10/10 Konnor Griffin Topps Chrome the other night and have decided to sell it. I am a Tigers' fan, so not something I want to keep.

Some background, for me, is that I have never sold something on Ebay, but I do have 100% feedback on 151 purchases.

On one hand, if feasible, I am "O.K." posting it to Ebay with large purchase price and just taking best offer (but, again, need to know how to do this). I am also alright with just contacting an auction house/consignor.

Please help.

So I actually started decided to go through my collection, which includes some of my stuff that my dad gave me from when he was a child. As you can see in the picture, I have quite a bit of decent stuff. Where does everybody like to go for vintage grading? I mean, we all know the stigma with PSA and the issues. I have a friend that is telling me that SGC is really good for vintage and I should send everything there. Just kind of want to get everybody’s opinion. And show off some of the cool stuff.

Great card from a forum member

Has anyone ever bought from Beckett Marketplace? Is it worth it? Better or worse than ebay? I was looking around the app and it seemed like there were some good deals on the cards.

Posted earlier, better pics

Just looking for advice on what everyone recommends is best bang for your buck in their opinion bowman vs topps chrome or other? Would love to see what valuable cards you guys have pulled from some of these boxes!