[Mikhail_Edoshin]

Marx's use of the word "exploitation" is misunderstood. Exploitation is using another person as a thing. Exploit as one exploits natural resources.

[lotsofpulp]

That is a poor delineation of exploit.

I use any number of professionals’ knowledge or skills or supplies just the same as I use natural gas to heat the home or water to hydrate myself or clean whatever.

Maybe something about the seller (or buyer) being under duress would be a start to defining exploitation.