Customs is very lacking in terms of loot, plain and simple. There's only very few ways to make money on the map and all of them are inconsistent.
First you have the marked room, which everyone and they're dog has a key for. And half the time you dont get it because you had a bad spawn.
Second there is scav boss, only 35% chance and in all honesty the ak's arent that good, and the majority of the time the armor isnt worth picking up.
Third is all the safes, which arent looted very often, but half the time they have nothing but insignificant amounts of roubles.
My solutions to the problem would be:
1. Buff dorms, there are already several locked rooms with keys with nothing but ass behind them, that could spawn nice barter goods and weapons like the health resort.
2. Buff the trailer park and storage units, and in general that whole side of the map, it has nothing of value but a safe and a few computers.
Anyway this is just my opinion, I love pvp in customs but as a lv55, I have little to no reason to play the map because it doesn't offer enough to me to make a profit I consider worth it.
Id love to know your thoughts and opinions on my suggestions and also also what you think they could do. Thanks for reading my extensive thoughts.