So, Reimu doesn't know what paper bills are?

She can't fathom food that could cost more than 100 yen.

At least Remilia's heart is sweet.

garand01 said:

So, Reimu doesn't know what paper bills are?

If we want to kill catgirls, they probably don't have them in Gensoukyo, given they hadn't been invented before the border went up. But even if they did have them, this is still probably supposed to be the first time she's seen one.

Also, paper money only has a live span of about 5-10 years when in circulation. So even if outside money made its way in it wouldn't last long.