I couldn't find NAS ones anywhere last fall so I bought a euro one from Paddocks UK for about $15 and had the one hole welded in and smoothed down by a body shop. You cant tell the difference from the orig NAS one on the other side.
I got mine new from RN and they were CHEAP. I cant remember exactly but for some reason I thought they were less than $10ea. I would tell you for sure, but I cant remember where I hid all of my receipts from the wife.