That's really unfortunate. Have you tried reaching out to them to get confirmation? I know a website that doesn't allow value adjustments on 200,000+ yen items but I've never purchased anything that expensive on ZenMarket. I think we may need a new proxy that doesn't have absurd fees and allows value adjustments.
Reaching out as we speak. Will update with any details. Though I'm not sure if they will simply make an exception for me, as I believe everyone should be receiving the same message.