Best deal/price on mylar buying in a few mniutes can someone direct me?

I'm about to buy some mylar, I'm looking for a good deal though, I need to cover a larger size, the opening of a closet. It has it's doors, but I don't know how I will cover the cracks around them which are about 4 feet apart and about 6-6.5 feet high.

Hmm, I was just informed that getting some space blanket from walmart would be the same quality, but much cheaper.

Yep Coleman makes em, they are huge and about $1.99 Look in the camping section, if you cant find them ask a salesguy - if you are worried about it, tell him you're makikng an emergency kit for a car