Wow!
Just curious, do you have to supply your own buckets or do they give you those, or do you have to return them? Which I could totally see them needing them back!
I bought the buckets, and leave them half. They fill them and then when I pick them off, I drop off the other half. Rinse and repeat.
I bought 40 buckets with lids, so any pickup is typically 15-20 buckets. More than 20 doesn't really fit in my truck, so I just be careful to not give them more than that at a time.