I have an FN PS90 sub gun and a RUGER 57 pistol. Both shoot the elusive 5.7 x 28 ammo. It now goes for $65. per box of 50!!
When I shoot 'em now it feels like shooting dollar bills - no, make that Euros, which are worth more than dollars. Even BC (Before Covid) the ammo was expensive at $30. a box of 50. Now the stuff is just either unavailable or out of sight in cost. I refuse to pay more than $40./box of 50.
Luckily I had the foresight to plan for a zombie armageddon/"militia" attack and have about 1,000 rounds on hand. But with 50 round PS90 mags and 20 round RUGER 57 pistol mags I can go through that SO fast. My "range toys" are becoming museum pieces. :(