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Cheaper: Depending on the alternative? Probably
Lighter: Again, depending on the alternative????
Safer: Doubtful. These things are pretty much foolproof and have been used in aircraft already for just this purpose.
       With a front hinged vent door I cannot see a benefit to using a manual mechanical method of operation.
       If you do use a mechanical actuator ..... don't forget to come back and close it.

 

All in all, it's sounds as those this would not be a good solution for you.