If the subject is sharp, then you'll be fine. If you haven't printed that size before it might be fun, but if you don't consider yourself a good printer, just send it to a custom black and white lab.
As for cost, I sell my 16x20's (which are really more like 12x20's if full frame 35mm) on fibrebase paper, matted and framed for $600. It's hard to ask money for a picture that isn't matted and mounted since they don't lie flat on their own.
And yes, it might take the whole 10 sheets to make the good print. More likely six sheets, but then what do you do with the other four. LOL