Thats an easy job for a water jet shop.
I made my own on a lathe but it would have been easier to send the drawing to my local waterjet guy and pick it up
Based on the last job he did for me which was four rear set levers out of 1/2" aluminum that was his he charged me $100 total. So I'd guess for one spacer maybe $25-50??
If you want to send me dimensions I'll draw it up in cad and send it to him or anyone else that needs a drawing to cut with.
We're not out here to rough it. We're here to smooth it . Things are rough enough in town.