Schwartz’s reasons for not using the full extent of his powers before are twofold. Firstly was the cost in CP. When up against the bird monster (Okyupete?) early on he splurged on the rocket launcher, a risky move considering his low CP count. But it paid off when he sold its materials for a huge amount of CP. From then until the green devil forest labyrinth raid with Sasanqua, he would have accumulated more CP, like from the monster train, but I suspect the bird gave him the majority of it. Secondly, the receptionist girl had sorta convinced him to be less reckless and to find a party, which meant he wanted to stand out less, to appear more human. Even in the end of the labyrinth guardian raid he has to care about his team members not treating him like some sort of monster.
But on realising that his purpose was to be some sort of labyrinth monster, and that his real body is deceased, he loses his attachment to wanting to remain as a human. He now has a more concrete goal, to become powerful and influential enough to rebel against whatever sent him to the other world. With less limiting tactics now at his disposal, and an extreme goal at hand, it is expected that he will act more recklessly, spending more CP to gain more CP.
As for allegations of a pay-wall, I suspect that there isn’t any such pay-wall in the game. Doesn’t really make sense to limit the highest future tech-wars behind money when you’ve doubtlessly got a bunch of rich VR-tank owners paying monthly subscription fees. There are also images shown of power-suits holding modern firearms, so it’s a safe bet that the power-suit Schwartz selected wasn’t a top-tier one. There are still energy weapons that he hasn’t even touched yet.
Since this does look like a textbook “lmao read the novel” kind of ending (like The Wolf Won’t Sleep), I guess I’ll need to find some way of doing that. Hope the author does more of something though, the art was pretty decent at the best of times and the pacing was alright too.