I think those measures are orthogonal. Often cheap goods are cheap because they externalize cost onto the environment. One example is recycling: better for the environment (at least in some cases), but costs more than just throwing everything away, often to the point that it isn't affordable.

A factor is that the they have scientist running around their lab growing it. That labor isn't cheap.

I thought those numbers sounded a little exaggerated and hand-wavey too. I highly doubt this takes into account things like emissions from vehicles used to transport the meats, for example.

The way these numbers usually work out is by comparing with the absolute worst possible industrial farming process (which is excessive in its pollution and waste).