Gamestop currently has Red Faction: Guerrilla Re-Mars-tered for Switch for $14.99 (MSRP $29.99). Available in store or online. Store pick up available but YMMV. Don't know if it's a sale or price drop but cheapest I've seen.
Note: Might be soon be hard to get for new. Amazon, Target, nor Walmart online carries it. None of my local GS stores had it and I didn't want to pay shipping for online. I just did a price match from the Best Buy online chat.