My DPMS carrier key is staked, quite well actually even better stake marks then my brother in-laws BCM he just bought so wouldn't worry to much bout it being staked (properly).
I'd be more concerned with quality of metal overall for $97 seems to good to be true but with stats like this it seems high quality
9310 Super Alloy Steel (7% stronger than Carpenter No. 158® Steel) Hardened Steel Extractor D2 tool steel extractor Black Extractor Insert Mil-Spec O-Ring Milspec Gas rings (3) Parkerized exterior
8620 steel Heavy Duty M16 design Grade 8 Gas Key Screws, Staked Parkerized exterior nano ceramic lined gas key and carrier interior.
8620 steel Parkerized exterior
416 stainless firing pin.