Found 9 1990 Topps Blackless Error Cards-Advise Needed

[HalfNipponese]

So I was cleaning out a closet to make room for some new cards and ran across an old shoe box with a bunch of “junk wax” inside. I found a card that look to have the same misprint as the Frank Thomas NNOF. The rest were put in the recycle bin. After looking it up and discovered there is interest in these cards. I decided to fetch them out of the trashcan and see what the value is. I listed one on eBay and the offers started flowing in. I (Edit: The big offer ghosted). I don’t know if this is a scammer or a legit offer. Unfortunately, I wasn’t able to find any prior sale info on any of them. Another buyer told me they were worth $750 each. I don’t know who to believe. A local guy told me to get them graded and send them off to a high end card auction house as all my cards are super rare. Any info or advise would be greatly appreciated. I pulled these from rack packs I bought as a teenager in Yokota, Japan.

BTW I found 2 Morris cards and one is for sale on eBay to finance the grading should I go that route. The pic was taken before finding 4 additional cards.