While perusing the "Ready to Buy" titles at my local RedBox, I noticed that Smash Ultimate is currently on sale!
Two things that may make this YMMV:
1. I'm unsure if the price for the game varies from city to city.
2. Not all cities have a RedBox that carries Switch titles. To see if your city is part of the initial wave to receive Switch titles, use this link here: https://www.redbox.com/switch-inf...12:18:2018
(Note: There may be some cities not included on the list that now carry Switch titles as well. Using the locator tool on RedBox's website isn't always accurate, so you may have to just visit your local box yourself.)
Best of luck!