Please let me know which cards from OP13 we have that are incorrect and need to be removed and we can look into that.

We have values for every One Piece set and all of the cards in English and Japanese.

Yes, TCGPlayer charges additional for shipping.  eBay prices are inflated by the included shipping cost.  For cheap, common cards the TCGPlayer values are much closer to the value of the actual item.  For more valuable items, the price difference is negligible because the value of the item is so much more than any shipping cost.

I've added that set now.

https://www.pricecharting.com/console/weiss-schwarz-japanese-disney-mirrorverse?uid=G103267

I can't add all the cards from that checklist at this time.  We will let users add the cards for now.  They can do that in about 24 hours.

Are those cards like this:

https://www.tcdb.com/Checklist.cfm/sid/70078/1933-40-Goudey-Indian-Gum-R73

Are these figures or cards or something else?

I have added those sales and others to those items now.  I don't see any reason why those wouldn't have been added earlier.  

Thanks for reaching out. I've added that set to our list of sets to add. We will add that full list in the next few days.

I'm seeing a sale for that game now.  Maybe that was the one you added.

We are constantly looking for sales data for items.  The values are updated on a regular basis with some items updated daily and others updated less often, depending on sales volume, popularity, etc.

I've added those sales now.

https://www.pricecharting.com/game/electronic-gaming-monthly/electronic-gaming-monthly-issue-2

I fixed a bug in backend that blocked those sales from being added from Magazine ebay category.

Please let me know some specific sets to add and we can work on that.  We need the full set name with the year.