This seller has some cheap Chinese prime lenses for both Nikon and Canon
Nikon 50mm F1.8 $16.88
https://www.ebay.com/itm/Yongnuo-…2749.l2649
Canon 35mm F2 $17.99
https://www.ebay.com/itm/YONGNUO-…SwK7xbdTKz
Nikon/Canon 50mm F1.4 $18.88
https://www.ebay.com/itm/YONGNUO-…tmja-jXxsA
I avoided the 50mm F1.4 because the lens has a USB port and needs firmware updates to maintain compatibility.