@Kiraidesu This is what I've garnered from both 30 seconds of research (I'm so in-depth, boooi) as well as inferring from contextual/linguistic/cultural clues
My assumption: ___pilled is a way of (more or less) saying that you're "woke" to whatever ___ is, in reference to the Red/Blue pill from the Matrix. In this case, "gachapilled" means you're aware of the true nature of gacha, and have, essentially, transcended beyond any state of mind where gacha systems could have a significant influence on you
"Based" is kind of the new "YOLO", but in more of a continuous-state-of-mind situation rather than an instinctual in-the-moment thing. Basically, you don't care what others think because you have enough self confidence and/or sense of self-worth to just "do you", as they say.
@Zonko
a common trick devs use with gacha rolls is they have a "premium" roll with the lowest tier stuff removed and the odds of higher tier drops significantly increased...for a notably higher price per draw, so if she's rolling that, then 1.25% for a 5 star rare isn't actually that odd