I would expect stem plants to come as cuttings. Most root fine if you simply remove a few bottom leaves and push them into the substrate. This is how you generally propogate more stem plants so I see no issues with sellers doing the same.
That would really depend on if they were sold as a 'bunch' or 'pot'.
If they are sold per pot, I would expect them to have been pot grown and have a deleloped root system, if they were described as a bunch I would be perfectly satisfied with cuttings.
So why buy plants with roots when they'll just grow back anyway ?
Well, plants with an already established root system will find it far easier to settle into your tank, uptake nutrients and start growing over plants that have to take nutrients from the water column and then
regrow a root system.
Thats why most places charge extra for potted plants (with roots) and this is something that should be taken into consideration when ordering. When comparing retailers prices you should go like for like:
For example, dont compare a the price of a bunch of stem plants from www.we-sell-cheap-plants.com to the price for a pot of Tropica plants.
I have ordered pots from some online retailers who have simple put a bunch of cuttings into some rockwool and stuck it into a pot and charged more ....... Y
eah like I reaaaaly want to buy a pot from them
Al