As a general rule, I don't recommend that you purchase a discontinued model when a newer, nearly identical, in-production model is available. That holds true for the Ascaso Dream Up V3.0, which has been discontinued and replaced by the Ascaso Dream ZERO.
Both the Dream Up V3.0 and Dream ZERO are quality, mid-level semi-automatic espresso machines built with high-quality components yet remarkably few additional features and certainly no fancy bells or whistles. That isn't a bad thing, because that means you'll pay less for the Dream Up V3.0 or Dream ZERO than a more feature-rich model, but it also means you need to work a little harder to pull a consistent shot time after time.
If you're looking for something more advanced or feature-rich, check out the Ascaso Dream PID. It's Ascaso's top-of-the-line home espresso machine and has a few truly transformative additions in the same compact, retro package.
If you're looking to save money by purchasing a used model, there's nothing wrong with opting for the Ascaso Dream Up V3.0.