headers 318i
 

I cant remember where they came from but my 84 318i has headers on it, was wondering what something like this might be worth?

In reality, demand for them would be even lower than the limited supply available. Nobody really builds an m10 to make power naturally aspirated and if they do, they'll likely be having custom parts made. Maybe find out if it will fit an e21 or 2002 m10 and try to sell it to those guys?