mylar vs home depot plastic sheeting

Is the stuff at home depot suffice for building a make shift grow room? Mylar is pretty pricey in comparison, isnt it? Thanks for the quick help!

You can get mylar at the dollar store its the shiny mirror finish wrappimg paper! Just open the end and look at the back if it has a pattern the back is usually still mirrored! Its usually 3x4 feet for a buck!