Seems to be the cheapest price for this movie. If you're happy with a digital 4K copy, this isn't a bad deal. Pretty much all of DCs flicks seem to be on say too, many animated features are $5 for HD versions.
Note this is digital copy and you don't get a physical disc.
Yes, "4K" on Google Play is not as good as on Bluray. Yes, you're buying a license to watch the movie and they can take it away from you at any time.
Edit: As posted below - $9.95 on Prime Video