Import from GameValueNow

Thanks for the suggestion.  Do they have a collection export tool?  If so you can probably do this already using their export and then our import tool.

https://www.pricecharting.com/collection-text-importer

You would export the collection and then paste the collection info into this tool and we would import everything and tell you which lines we couldn't match up and you can manually add those.  It is usually less than 1% that need manual entry.