Too cheap. I suspect we arent getting the entire story. Subs are one of the biggest areas for black budgets. I would not be shocked if this is the final purchase of objects the navy has already spent billions developing.

Not final.. just the 2nd step. They previously awarded ~$40m (each) to boeing and lockheed for the design phase. This phase is for prototypes of the vehicles that were designed. There should be a 5th that should be awarded to Lockheed. In a few years, then they'll start production.

Edit: This is part of the Navy's plan to develop UUVs. They've already spent billions on it. On page 4 of this you can see the UUV systems they're planning: https://www.navsea.navy.mil/Portals/103/Documents/Exhibits/S...

This year they have $210m allocated for just XLUUVs ($120m) and LDUUVs ($90m). And I'm sure they have more allocated for other parts of the program (Edit: $1b this year for navy underwater drone r&d, and they spent 7-800m last year on it too).

Edit: XLUUV has a few other parts too: there's projects for developing lethal and nonlethal payloads for it; and a payload delivery system.

OTOH they're probably a lot cheaper to build if they don't have to support human life.

OTOOH, any and all maintenance requires return to base or abandonment at sea +/- self-destruction.

Giant as far as robot subs go though.