You get discounts on most of the popular plug ins, NIK, OnOne, Site Grinder, etc. You get free shipping form B&H. There are hardware discounts that are too numerous to mention.
I joined NAPP when I first started going digital and the tutorials helped me alot. Overall I feel that it is a good 99.00 expenditure. I have attended several of the seminars that they give around the country and you get a discount on them as well. I've certainly spent that amount of money on things that are more foolish.
I do agree that if you want something that is going to teach you photoshop then have a look at Lynda.com. I have not tried Kelbytraining.com and have seen mixed reviews on it. They are still fairly new and building up their library of courses. Lynda certainly covers a much broader range of subjects if your interests extend beyond Photoshop.