cheaper to make own grow tent?

i want to make a 6 foot by 6 foot by 8 foot grow tent and was wondering if you all might have some ideas for me. i was thinking of using a pvc frame and stitching waterproof canvas tarp together and lining it with mylar or something. how would i use the mylar just glue it to the canvas? i just want a good grow tent and dont want to have to spend like 700 bucks for a tent so any ideas would be great and thanks for reading..

was up cryptic i been searching the net looking to start my frist grow think im gonna go tent also they have some cheap tents for 200$ and below 1 is 48x48x48 i (think) for around 150$ check ebay or cheaptent.com or htg supply.com might not be as big as you said u wanted to make.

GL