Paper costs about 18 euros per 100 sheet. paper has to be A4 size, Legal-size I think in US.
170g/m³ is the thickness of the paper, normal printer paper is 80g/m³ or 90g/m³
I have printed now 10 NES covers with the inks that came with printer, and I'm used about half of the color ink, black seems to be full.
Ink cartridges that come with the printer are never full, usually only half or one third full.
New ink cartridges cost about 10 euros.
So I estimate that price of one cover to be about 10-15 cents.
BTW: I still have 600+ covers to print.