When you open a new booster, there's a 25% chance to get one of those cards instead of the marketing one
However, a better alternative to DNA Transplant would be DNA Surgery, which allows for the conversion of all monsters on the field to a selected type rather than attribute, providing a more versatile effect and seeing more play in various decks
With a workable Grass Weakness, I could see Blastoise being played in an Aromatisse deck in the Expanded format, however, that format might be too fast or disrupting for an Aromatisse / Blastoise deck to flourish
He also uses this Deck for the Momentum Reactor's dark miasma duel gauntlet
The short answer is no at least not in its tabletop form
Japanese versions of the next hot ticket Pokmon card Team Rocket's Mewtwo ex have hit the secondary market, and are currently selling for upwards of $400