It was all an enactment to make Linda believe she was being sold. That is why the MC paid more than the original debt (he paid for the show). The fact that he offered that amount was his own flare for dramatic effect. This is why he gets angry when he is told he has to pay 250,000 now, he is being taken for a fool by Liling. I suspect that in the future he will bring liling dawn a few pegs for her insolence, if you check the stats page you can see that Liling has submission instead of love points.
While the MC does own a business related to hostage and abductee rescue, it also appears that he is not a heroic character. The MC is not a knight-errant type of character, think of the MC more like a mercenary, that way you can see why he does not act against Liling from the start.
Hope that clarifies the issue.