The guy said he made an error on his end and he had to sell them fast to recoup money or something like that. Something with his inventory management I think. Just got mine delivered and waiting for the FFL to call me.
Saw this on Reddit but reposting it for those that don't use it.
Yankee Hill YHM Turbo T2 5.56mm Suppressor
https://www.mapguns.com/products/yankee-hill-841812100201-yhm-2125-5m2-4389
Use coupon code STAYSINVEGAS and it is $300 shipped.