Those are not full custom chips.

They are stock artwork with a minimal change to suit the customer.

There is no way, I MEAN NO WAY, you can get any quantity under 1000 chipcos designed from scratch, made and delivered to a US address at under $1 each.

If its B&G chips then add 20% minimum.

"Americans don't pay import duties from stuff coming into this country"

Oh yes you do when its from a commercial company.