There are many options, some are used, some are new, pricing can be $65 for a PASGT - right now - but those are used 1980's model helmets. If you want new and certified and don't want to spend $700-$1400+ this is a decent option. Not everyone wants or even needs a 30-40 year old helmet for $65 but for those who do, this option is available.
Since these are NIJ Certified they're great for LEO who want their own helmet or prefer a different cut or options as unless they use their own money they can't buy the Chinese-Knock-off's for $199 off Facebook or a used helmet that's 2-3 decades past their service life.
For real though. If you are buying it and using it in service buying a used/Chinese helmet is pretty shady.