Hi there, I am one of those professional plant people, and I deal with dracaenas a lot. I had a long chat with the wholesale greenhouse lady where I buy my plants about dracaena marginatas recently. She told me that when they are grown in Florida, they grow them under very high light with lots of fertilizer, so that they grow fast. Time is money, the faster they get the plant to full size, the sooner they can sell it and use the space to grow another one. With all of this light and water, their leaves are very firm, to the point that they can give you an extremely painful poke in the eye, like being poked with a stick (don't ask me how I know this...) A plant will keep these stiff leaves for several months after being put into its office location. If the light is very bright, the leaves will stay stiff. If the light is dim, they will gradually start to droop over time. Once they droop, I don't think they can get stiff again, at least not those particular leaves. The droopy plants that you see the plant company caring for probably only need water every two to four weeks, especially if it is dark and/or cold. I do not recommend moving marginatas into cold. They do not like cold at all, and it will lead to the lower leaves turning a mushy yellow, along with all sort of possibilities for root and stem rot. Marginatas do like to be kept dry, especially if they are in a dim location. Not as dry as a cactus, but pretty darn dry. When in doubt, err on the side of not watering. The ones you see the plant company take care of with the stiff leaves? It is quite possible that they remove them and replace them with new ones periodically, and that is why the leaves appear to stay stiff. Hope that helped!

here is the picture

Well, in their defense... Yesterday the HVAC guy ran into much bigger problems than he expected so he was at my house longer than they scheduled. BUT he called in to base and reported it so that they could make arrangements with the next person on his list. I guess I'm lucky that he was delayed at my house and not on the way to it AND that this business respects their clients enough to make the tough call to say we're running behind or can't get there. In this day & age of everybody and their mother (or their 5 year old) having a cell phone, there is no excuse for not calling you to report the delay or reschedule. Why would they want to show up at the next job with the homeowner already annoyed with them? We all can understand problems develop but there's no excuse not to call & tell you that. I guess if they're the only game in town they feel they can be rude but it's really basic human decency, along with good business practice, to do what you can to keep the other person informed and prepared. That guy has some bad Karma coming his way.

I have some that look that way also. Mine are grown in full sun which does affect it's coloration. Some also have those markings. Right now mine is more yellow, bright green and bright red edges.