I don’t have one for sale, but I was able to grab mine on an Amazon Warehouse deal so you might want to keep an eye out for them there. I just checked the page every day for a week or two and one popped up with a good discount from new.
Might be able to get away with unbuffered ecc memory on this board, would let you get 2x8gb/16gb in there. A couple sticks on eBay right now for ~$11/ea.