As a "hobbyist", you had over 25 for sale threads in the past year including threads selling auto to manual conversion kits at $2300 each. Given the volume of parts you have been selling (and the types of parts listed make it difficult to believe you are selling "your own used parts", e.g. simultaneous listings of a 280 kph gauge face and a 180 mph gauge face this month), that puts you in the vendor category.
Yes, it is true that I've probably listed a lot this year as I'm having a clean out to try and pay for a new project, But that doesn't mean I sell that much. I haven't sold a conversion kit in a year & a half. So just based on that i'd be out of pocket $750. yes I make a couple of parts but am far from mass production, most of the used parts I sell were fitted to my own NSX at some point.
If something could be set up similar to ebay where we pay a fee when we actually sell something I think that would be fairer for us smaller "Vendors?"
I'd much prefer give my money to NSXPrime rather than Ebay so I hope something can be worked out.