I'd choose a material that is easy to install/remove and works well for the customer.
Something along the IJ35c or IJ40c depending on price.
It goes on easy with air release & comes off clean with removable adhesive.
C series of IJ has the gray glue to help with block out.
There is most likely another brand that is cheaper with the same performance - you need to look around - AirMark or something from BigFish (material merchant here).
You can find some dirt cheap crap vinyl but the problems you'll run into with install - staying up or not coming off without a mess will soon eat up any savings you might have counted on.
wayne k
guam usa