MC always got scammed and taken advantage of. Maybe the author want to use this as some kind of Punch line comedy but failed miserably. I mean if you want it as a comedy, you can probably put funny tsukkomi here and there. Or maybe it is not intended as Punch line, but to frustate the reader.
Dont waste your time with the novel, it is completely different.
The story of the manga is pretty light and warm hearted. The MC in manga is quite laid back.
While in novel, the MC is very ambitious, and not warm hearted story.