I had a source for unpicked, recent U.S. kiloware - truly unpicked as even priority and occasional express mail stamps were present. Unfortunately, that source dried up.
What I would do - pick out what I needed, put most of the common definitives, love and Christmas stamps in the recycling bin, and then sold the remainder (which was then mostly recent commemmoratives) on eBay
. I usually made a small profit on top of filling spaces in my album, and the buyers were always happy too.
I don't regret removing the "dross" from circulation. There's plenty available elsewhere and I leave enough in the batch for the next picker to get them if needed.