I have learned by mistakes not to assume, if they don't state the size ask! I think a lot depends on how big a hurry you are for your plants to reach a certain size. I am cheap, so I always go for the smaller (not tiny) plant if the price is high, the larger plants when the price is cheap. I don't mind waiting a year or two for the plants to grow, in fact I grow some from seed just for the fun of it. I think most plantaginea are fast growing hostas, so for me the smaller cheaper ones would be the way to go. I guess the difference could be tissue culture grown on not also, something I guess you might want to check on. That's all I know to suggest being I have not ordered from any of those sources, and that might be what you are actually asking about, so no help there.
