>> Costco/Sam's club
Now I know where to go if my curent roll ever runs out! (Gee, now that you mention it, that WAS where I got my second roll. It was way cheaper than the restaraunt supply place 20-30 years ago!)
>> "el dinero!!!"
The "Saran Wrap" method becomes almost free if you already have a wide roll, since rinsing them off lets you reuse them for years.
I don't think taped-together lengths of 12" film would be easy to reuse. That's not very sustainable, just workable for someone with a tight time budget.
I agree with you that reusing something you already have, or that you can get from neighbors, is the most sustainable method.
My "baseline" would have been buying more of the rigid "humidity domes", GRAMS of thick plastic and multple dollars each. That's like a 'worst case' and yet many people buy those domes.
I never have had dry cleaner bags, though it might be neighborly for me to spend time meeting neighborhood strangers by asking them for something.