It looks like the item pages here on CGTrader are not displaying correctly. I had the same confusion until I realized what's going on.
If you look at the creator's store and find the model there you'll probably see it shows a 30% discount. This is the ACTUAL discount currently applied to the model.
When you then click on the model to go to the item page it displays a 50% discount. This is INCORRECT since, as previously noted, the item is only 30% discount.
Hopefully they fix it because I almost spent way more than I wanted to. I caught it at checkout.