How to determine the grade of Insulated Copper Wire

Hello, this may seem a dumb question to most but I just want to know if I was trying to be ripped off. I have been scrapping steel for a while now but recently I got a job as an electrician apprentice and have accumulated quite a bit of scrap copper wire. Most of it is insulated wire used for controls. Thats what I was trying to sell today. My local scrap yard is paying $0.93/lb right now for insulated copper and they do not have different grades, it is all the same if its 10AWG solid wire with the insulation or if its 18AWG 4 conductor wire. What I was trying to sell today was about 200lbs of insulated scrap wire that included 18/2, 18/3, 1/4, 18/8, 22/3, 22/ 2 pair, and it all had the PVC jacket on it with an aluminum foil jacket inside around the stranded copper wires. My local yard couldn't take it today because they couldnt get a hold of anyone from my job to verify I had permission to sell scrap wire although I had a letter from the company stating I had permission, they still have to call and make sure. I ended up leaving and driving 30 minutes to a scrap yard in North Carolina and had already talked to them on Facebook and they were paying $0.60lb for #2 insulated copper wire but offered me $0.75lb since I had 200lbs, when I get there the guy tells me that its not #2 insulated that its actually 2 19? and he will only give me $0.20/lb for it. I told him thats crazy i will just wait and get 5X more from my local yard. I just wante to know if I am wrong about the grade of my wire. If anyone needs further information about the wire I have just let me know.

Grade should be based on recovery percentage. Use a one foot piece as a sample, weigh it then strip it. Weigh the copper then divide the copper by the total weight to get the recovery percentage. Higher the percentage the better the grade. Start talking percentages with those guys and they will figure out pretty quick your no average Joe.