I usually just get plants through local club auctions, but sometimes my local Petsmart will have some of the tubed plants at a 50% discount if there's dead or browning leaves, which is pretty much the only times I buy them. Never had any issue with them dying, though, and they generally seem to be of good quality.
Except the java fern; last time I bought a few, they were just leaves and one or two tiny rhizomes bundled together with twine- there wasn't even much effort put in to disguise the fact that half the "plant" was just stray leaves tied together. Might be different now, though; not completely certain.