There is a review of a JG G36 on these boards, with photos.
So if we use that as a price base; let's say $300 and comes with one battery, one mag, and one cheap charger.
You still need protection for your face, clothing that wont make you stand out like an orange flag in the woods, and ammo.
Then you most likely will need to buy a far better battery charger/discharger and a spare battery, and a spare magazine or two.
From what I saw of the internals, you better be good at upgrades and repairs. Save cash for spare parts in there too.
$180? You might get a gun for $180. How long will it last? That is the question and the choice you must make when you choose the quality level of what you buy. Future upgrade or repair costs must not be forgotten. Mechbox parts are not cheap.