@beach-mom I haven't looked at the two item numbers you are referencing, but I know QVC sometimes has bundles or special colors that might be more or less expensive. As long as both are Dysons, they are using the same technology.
I have a model that the Q doesn't sell any more, it came with far fewer attachments than are now available. I don't often blow dry my hair, but I can tell you with confidence that the Dyson blow dryer is very much faster than any other brand I've ever used, and leaves my hair smooth and shiny, where other brands leave it rather frizzy, which, with my straight hair, is certainly because the heat is frying the hair. I won't use any other brand of blow dryer on my hair; it's aging, right along with the head it's growing out of, and doesn't grow as fast, so it needs more pampering than it used to.