They should be okay money wise. The dude made 390k definitely-not-yen in the previous chapter. There's no way Liz's mom would have accepted that much even if he had offered all of it to her.
Or maybe he really lost all of it. Japan worships destitute heroes, after all. But in that case you'd think the mother would have used a portion of the money to buy equipment for Liz. She wouldn't want to lose her daughter, after all.