Definitely not surplus ammo. Theres both not much out there to surplus, and it's all AP, so would not be sold to the civilian market.
5.7 was stable in price for a long time (2008~2018) at $0.36 per shot for SS197 'blue tip' VMAX rounds. Then 2019 Ruger's 5.7 pistol is released, greatly increasing the number of shooters for 5.7, and then Covid + Summer of Love hits, then more 5.7 pistols come out, and now price is totally nuts for 5.7.
Fiocchi is now expanding 5.7 production, planning to 3x availability in the US. Also they've just introduced a neat 62gr Subsonic load.
And probably the most exciting is PSA's new ammo company is planning to release their own 5.7 ammo and loads - rumored to be hotter then the legacy rounds.
https://www.ar15.com/forums/General/...583807/?page=7