Depending where you are, hang it 10ft high, 6 ft from the tree. That's what the scouts recommend at the high adventure camp in New Mexico. And that's what I'd do out west. It's tough to do when there are no horizontal limbs 10ft up. Mostly I try to keep stuff in plastic bags to cut down on smell, and get it off the ground and as high as I can, even if only 5 or 6 ft up. At THIS CAMPSITE, I put the food in nylon panniers and strung a line between the Adirondack shelter and a near by tree, the tree just to the left of my kid in the image.

$70 seems like a lot for a 10L bag. I've picked up 50 and 60L dry bags on sale at REI for $15ish. Not as tough as this stuff, but I'm going to hang the bag anyway.
Just - whatever you do - don't bring food into your tent and don't smell like food when you close up for the night. (advice worth way more that 2 cents)