Well hush my Puppies, I worked at a nursery and they did it all the time. The suff back then was over $50 an ounce. If you check the company out you will find out about it.
The company I worked at used for special plants , when they only needed a few thousand plants. But they only had a few million plants . around 5 million. They only mixed potting mix with a 3 yard bucket Huf. front loader.