360 feet - is that one 12 x 30 run or a 12x12 and a 12 x 18?
yes, the materials for that specific product are pricey, because they're a specialty item, but the contractor was quoting pretty high for his labor as well. (comes out to $15 a square foot installed, so I suspect he was doubling his $$ on materials and then figuring $65 a man hour for him and a helper for 16 hours. either that or something like $12 a square foot for the materials and $1000 flat for labor.)
lowe's sells 29 ga galvanized corrugated steel for a reasonable price. 30" wide by 12 foot long, so no cutting. 13 or 14 sheets oughtta cover all the ceiling you want.
They also sell the hex head barn screws with rubber grommet so the screw holes don't leak.
If you really want to make it last a long time, degrease the sheet steel and paint it on both sides before you put it up.
if you've got a buddy/child/neighbor to help, you could do this in a weekend for less than $500, a pizza and/or couple of steaks and some cold carbonated beverages.
OTOH, vinyl looks better from the get-go, but materials will cost more and it won't last as long. (wifes generally like it better - because it's prettier)