I've had a terrible time with roofers, it's nearly impossible to get someone out for anything less than a complete roof.

I'd like to get a ridge vent to help cool the attic as my bedroom is part of the finished attic. The cheapest contractor suggested an aluminum ridge vent-something no other roofer suggested.

What's the difference between a single ridge vent versus an aluminum one? (those that tell me one is aluminum and one is shingle will be haunted by a ghost for all eternity)

Can you tell me the pro's and con's of each?
sorry, I mistyped. as the title says, SHINGLE, not single. What are the differences between SHINGLE and aluminum ridge vents?