I'm not sure if this is nationwide or just select Costco stores. I bought 4 over a foot tall tomato and pepper plants for $12.99. So a little over $4 a plant. I think they are 3quart pots because the flat of 4 says 12 quart.
They look pretty healthy and I can trim back to clone some of the multi stems and large branches to root multiple plants from one as well. If you trim back large stems or large branches you can start a new garden plant two ways. Either just stick them in the dirt and water well or use root powder . I was at the Danvers, MA store.