I hiked for years without using poles, then a friend turned me onto them and now I won't go without them.
My last time up Whitney (end of May) I bought a pair at the Whitney Portal Store and can report they were of great quality and cost less than 40 bucks for the pair. I leave tomorrow to go again and will use the same pair.
Truth is, I don't know why someone would say don't bother with poles, unless if that person didn't know how to use them, and therefore got no benefit. If you just swing them around like little sticks you're not using them right. They want to help push you up the mountain and control you while descending, taking the pressure off your legs (who speaks for the knees?). Plus, they will help your balance as you exert in the high altitude.
Two thumbs up for trekking poles from AdiosRich!
Those plastic water bags with the tube that comes out like a flexible, three foot straw is another thing I won't do without. If it is easier to drink you will drink more, and if you drink more you will be a happier hiker.
Two thumbs up for those plastic water bags with the long straw thing from AdiosRich!