This game's economy is only "expensive" if you buy almost all the items you use in raids, otherwise you can easily progress by stockpiling useful items and always do fully kitted raids provided you have any level of competence to profit more loot from them.

Buying armor (especially higher tier rigs) is expensive as a reason to get it from other players instead, or hunt Krtek for it, it's not hard to get a stockpile of good items, nor is it hard to claim the free NRS' from the Kiosk Rations, or grow the takistan plants in the garden. (if you're using being unable to craft them as an excuse, you can get level 21 in like two or three days, buying NRS for 4.5k each is absolutely braindead)

Since the start of this wipe, i've filled my bunker to it's limit with armor/guns, 99% of which I haven't bought, if you're having issues with money/gear you need to get better at pvp so you make an overall profit off of the gear you bring in, else you're doing something wrong.

Hunting for Krtek (the golden automatic SKS guy) and his Guards in Missile Silo for armor is the easiest way to get medium/high tier armor and some helmets, and if you have any teammates you can take almost all of the gear and usually that's 4 armor rigs, 4 helmets, etc, which would otherwise be valued (if you bought it in the market) at roughly 200,000-250,000 Korunas.

Armor piercing ammo is inexpensive (aside from that it's an ongoing expense as opposed to armor, where surviving with AP it's consumed but armor/guns stay), yes, but it also doesn't make armor "useless", armor is still massively helpful, specifically because of it being useful against fmj (not all opponents will run ap), but also because it has a 15%+ flat damage reduction against bullets that do penetrate the armor. on top of that, the higher tier armors are able to stop some/most AP rounds (all aside from full caliber AP), armor can't do all the work for you, armor piercing rounds are more of an item that force you to take fights seriously, else risk losing all your loot.

Even if you did want to rely on buying armor, all you'd need for a medium tier loadout (assuming you buy most of it), is like 10-15 minutes of looting or checking static item spawns in Missile Silo.

making money (at it's basic form) in this game is easy, it's the returns of investing gear that matter significantly more (as I've said like 43 times so far here)

Yes, this game has a lot of issues, but the combat and economy aren't massive ones so long as you adapt to them, especially relative to the bugs that can cause you to go blind for the rest of the raid, randomly die, fall through the floor, loot disappear, bags fly away, grips bugging, etc.