@Lost_N_BIOS - I checked both ebay.com, ebay.de and ebay.it (I’m ordering from Italy). The thing with imported boards is that the shipping expenses are of $50. If I don’t find anything else I may pay them, even if it’s a little weird to pay almost as much as the actual price of the component just for the shipment. 
I found some cheaper ones ($70-90) on Aliexpress, but I think they’re OEM non-Asus boards (I meant this, sorry for my poor phrasing).
Here are two of them for instance:
https://aliexpress.com/item/32862050120.html
https://aliexpress.com/item/32904835118.html