Yeah, it’s almost like they price them based on their equivalent weight in gold (stolen poorly from someone else on this forum).
Good luck! I just got my first two manga in the mail in an attempt to improve my Japanese reading, Yotsubato (よつばと！) volumes 1 and 2. I have my eye on getting Dragon Ball too but my real goal is to be able to read Diamond Ace!
I’ve tried the same with reading manga and gotten a bit frustrated or de-motivated with it at times because I’m not quite grasping something. However, every weeknight I watch two episodes of DragonBall in Japanese with Japanese subtitles on and attempt to understand them. What I find interesting is that there’s still some/a lot of things I don’t grasp, but I don’t get frustrated as I’ve moved on to try reading the next line of text. What is motivating is that even not understanding everything I usually get at least the gist of what’s going on. The more I learn, the more of each episode I’m comprehending.