Buying from local heating company

I was at the yard yesterday and I a heating and cooling company was selling furnaces and all the compressors and motored as shred. I think I'm going to approach them to buy the compressors from them at there location for a certain amount and do all the loading. There industrial ones probably weighing 100-200 pounds. How do I do this I don't have a scale do I just buy per one or what. Never have done this?

find a place nearby with a truck scale. usually you can get weighed for $5-10. you need to ne weighed before and after pickup.

I usually eyeball it and pay 100 bucks a ton. Most owners are happy with my guesstimates as they usually don't have a full trailer load.

Offer to pick it up from the job site instead of paying...some loads are better then others but it averages out.