We're hoping for a permit for August, and having never backpacked before, are starting to stockpile gear. Husband saw a sleeping pad at Costco today that's 3 inches thick & self-inflating (brand: LightningSpeed), and only $35! Seems like it'd be comfy for a side-sleeper like me, but these babies weigh in at 5lbs! Is the comfort worth it, or should I start training myself to sleep on my back, and get a thinner (lighter!) pad?

Thanks!