Best budget grow medium

I find myself buying bag after bag of fox farm soil , so my question is what's the best budget grow medium ? I've been looking at coco . What Do you use and how much does it cost ?

Bcuzzzzzz soiless hydro mix. ......38$ a bail. Great results......DWC is the cheaper route with bigger yield from my experience though

If you can find Pro-Mix you can cut some of it in with the FF and stretch it out longer that way.

Hydroton as far as price and efficiency, just wash and re use which is not as easy as it sounds........