I tried to buy an actual barrel of crude oil (2015)
Back in school (around 2006) I asked the PR department of German BP for a  small sample of crude oil, that I need for my final assignment. A few weeks later I've got large glass bottle (I think maybe over a liter) of crude oil. The package needed the signature of my mom because it was a dangerous goods transport. I think the shipment was for BP more expensive than the Russian oil itself...