Yeah, if you don't expect to utilize it's "highest use," it may not be worth it. By highest use I mean experiencing the conditions the garment/equipment was designed for. That $150 wind breaker was most likely created out of a fabric that is lightweight, can be compacted and crumpled into nearly nothing, block the wind and keep you dry. When I was hiking up to the Harding Icefield last May, I really appreciated all those capabilities of my REI shell. Had I instead dug around in my small pack to produce a walmart -veritable- garbage bag with poor seams and hefty mass, it may have gotten the job done for the time, with some added discomforts. Instead, I invested in quality, and expect it to last long and treat me well. But I've already used it on several overnight excursions where it's proved itself. The same applies to the hiking pants, rain pants, gaiters and packs I've bought. You can get by and still have fun with cheap (or completely lack of) gear, but I imagine small investments here and there will ultimately produce a more comfortable experience.

Cotton socks on a long hike? Enjoy athletes foot. Rain storm 5 miles from the car while wearing jeans? You're going to be cold. Hurt yourself to the point of immobilization while wearing such? You're risking more than discomfort.

It is a cost-benefit analysis. I feel like I do enough of it to warrant the purchases.