Update: I paid $80 for a bucket of dirt from a "dig site" on eBay and got rocks from a driveway in Ohio
Seller claimed it was unsifted matrix from a Mississippian mound, but I found three pieces of gravel and a bottle cap from a brand that didn't exist before 1962, so now I'm out $80 plus $12 shipping and wondering if anyone else has gotten burned buying "unsearched" dig material online.