I would reccomend to buy fast growing plants from there such as stem plants and mosses, because even if you get them and the health of them isnt great, they will soon recover and you will have a large bunch of fresh healty plants.
For slow growing species, such as anubias, cryptocorynes etc i would buy from either "the green machine" or "Aqua Essentials" because you get a very large, well established healthy plant for the money, and it is well worth it.
When i bought slow growing plants from Plants alive you got 1 leaf on a small rhizome - not worth the money at all.