Where I live in Oregon, retailers just fill the tank. The price locally is $2.59/gallon. Twenty-two miles away, at the local dealers yard, the price is only $1.69/gallon.
They get all their propane trucked in from the western terminus of one of the major pipelines in Bend, Oregon. That is 120 miles away, over the Cascade Mtn passes.
No, their tanker truck has never had an accident, and blown up.
At 4.2 pounds per gallon that’s pretty cheap. I think I paid about $3 per gallon last time. It was about $14 for 18+ pounds.