Shrike himself is far too shy to be willing to share a room with others, so he prefers earning enough to pay for something himself. Even if it's small.

But more importantly, being thanked for his help and told it's useful really feels nice.

"Oh, um, good. I mean, it's good that it's useful."

It's a pity there's no chance of seeing his face right now, his voice alone probably conveys quite a bit at how thrilled he is to have helped.