#2 vs. #3 insulated copper wire - questions

So I'm new to all this, just a little side money. Mostly I just take cords I find in the dumpsters in my complex. Line cords, zip cords, USB cords, Ethernet cords. And when I take apart electronics and appliances, I get some single-wire insulated. It all just goes in one big carton. Now the carton is full, and it's time to take it to a yard.

Some questions:

I'm not 100% clear on the difference between #2 and #3. Can I assume if it's all in the same box, it would be counted as the lowest grade? Is it worth sorting? I'm talking about a carton that weighs 30-40 lbs.

And speaking of #3... most yards around here list only #1 and #2. Does that imply they don't accept #3, or does that imply that anything that isn't #1 insulated pays the #2 price?

Thanks in advance, friends!

Grade is based on percentage of copper to total weight. Ask your yard what % they grade on. Take a foot of something and weight before and after stripping...then sort the like percentages. If you go to the yard knowing what you got and tell them..the better price you should get cuz they know you did your homework.

Some yards use #1-3 for grading copper which I think is kinda hard to get used to. the way we grade copper at my yard is 80% which is mostly MCM(big power cables), THHN, and romex after it got the outer insulation removed. Then its like 70% which is romex and well pump wire mostly. Then 50% #1 which is like ethernet cables and such. Then its 40 and 50% #2. 40% is like extension cords and pretty much everything else. 50% is the old style house wiring and power cables and what not. Then we got battery cable and Wire harness (Auto Loom) which are their own things because we do enough cars and run enough engines through the hammer mill that it makes it worth it to separate most yards probably don't. It sounds like you have mostly low grade, (40% #2) or #3 at the yards that grade like that. But I could be wrong.

A yard i use has these grades for copper wire,

#1 House wire
#1 Wire 90%
#1 Wire 80%
#1 Wire 75%
#1 Wire 65%
#2 Wire 60%
#2 Cat5
#2 Wire / ext cords
Harness wire
Xmas/tv wire
Heliac wire
Low grade Heliac