As noted. Buying x number of bags, renting a small electric mixer, would've cost just as much, taken longer, than getting it pre-mixed in this mixer, or a non moving metal box trailer then pouring either out.
Issue with the metal trailer, is stuff can settle as you drive down the road. This it does not.
This place also had a few single axle lcf trucks with will swag a 4 maybe 5 yd drum on them for local too. not sure if it is a tent and drive truck, probably not as they had a mid 30k gvw sticker, air brakes etc. They are very well st up for what I would call local under 20-25 miles away deliveries.
Both my son and I have used the non barrel trailers. This was a much nicer way to pour etc the concrete. We both admit, it would have been nicer if a 3-4' chute or two could have been attached.
Marty