Well with a check, it'd have to be written in your name and you'd have to present yourself most likely. Doesn't sound like you have a bank account to store your money so I suppose cash is the only possible option.

When you have time, you can come over to room 102 in the hotel to drop it off. And...thank you for your help.

[Yep hell's freezing over a second time because Saori gives him a small smile.]