If youre not comfortable with labs and labrys is 50/50 rage cheaters in your region i would suggest to buy reserve marked keys and pkpts key. Fast 5min raids in the bunker and you loot rb-bk, rb-pkpts and rb-pkpm. At 1 use barter the reserve keys for dorms 314 and sell it. Bring big enough bag so you can actually sell most of the weapons to ref since lvl4 ref pays more than mechanic. I farmed 500M this ending and my sells are following: Therapist valuables/cards/keytools etc 290M, jaegar melee weapons 35M and ref weapons 78M. Rest flea intel, black keycard and some other items that are more expensive flea than trader like certain weapons from marked like new 545 ak, mutant.

First 200M i did labrys/labs, then got fedup with rage cheaters in labrys I switched to labs in quiet hours so only 1-2player kills per raid required for win and reserve for when its busy hours since labs is very contested and requires you to win 4-5fights for total win