While I do wanna give MC some flak for not price-checking his wares, his means of production are different, so this is honestly not a bad deal for him. It draws attention and tanks the local economy, but as established in the first chapter, f*ck this kingdom.
Slavery, huh? The perfect employee/bodyguard for him is in a pinch! The question is, will he pay off her debt and hire her, or just outright buy her? I mean, either way she'll be in debt, but there's still a bit of a moral difference between taking a corporate slave and literal slave.
I mean, he could also pay off her debt for free and she can follow him out of personal loyalty, but somehow I don't like that idea. It draws even more attention, gives me a bad self-righteous aftertaste, and is kinda emotionally manipulative on a narrative level.
As a side, she really should not be using swords. For someone with as much obscene strength as her, blunt weapons would work better-not to mention she wasn't very good at avoiding unnecessary clashes with a sword.