I agree that the likely result is that lab-grown meat will most likely cost more. I'm just not sure that not-lab-grown meat will stay cheap. The unseen environmental costs of raising livestock are not currently well-represented in its price, which is also heavily subsidized (both financial subsidies and unhandled environmental externalities). And there's not enough land in the US to put all of its livestock to graze. There's water supply problems for livestock and feed (which takes 10x resources to grow compared to simply growing plants). So if, on top of that, you introduce mitigations that reduce profit somewhat, the price will have to go up even more.

Factory farms are also currently benefitting from economies of scale, something that plant-based meat manufacturers are only now catching up to. Plant-based meat's ingredients are generally pretty cheap compared to the cost of raising livestock, so theoretically they could potentially beat the cost of meat.

My non-expert hunch is that its externalities of lab-grown meat will be somewhat different from factory farms. Time will tell if they're better, more sustainable trade-offs.