That, and the fact most outdoor-gear buyers are in turn pretty savvy, means that the majority of outdoor gear on the market represents pretty good value for money. I'm not saying that to be an apologist for gear makers, who did seem to take leave of their senses (along with lots of other people) during the late 1990s and introduced one too many $500 tents. But for the most part I don't wander around the Outdoor Retailer show each summer clapping my hand to my forehead thinking, "That is the stupidest/highest-priced/most ridiculous thing I ever saw!"
To sort of answer the first part of the question, I suppose that some day I should compile a list of 10 Stupidest Outdoor Gear Inventions. Without naming names, some things that might make the cut would include boots that had little retractable spikes in the heels; one-piece rainsuits that were marketed, very briefly before disappearing, for $1,200; and almost any item that tries to sell the buyer on a "system," such as packs where you buy one suspension system then interchange bags for day hikes or weeklong trips.
On the useful-but-too-expensive side, I often cite the case of Activent, a fabric marketed by the Gore-Tex people four or five years ago. It was billed as a highly water-resistant, highly breathable material for use as a light shell when running, biking, hiking, and the like. It was fabulous—maybe the best performance fabric ever sold. But it also was expensive, and people were asked to pay $200 for a jacket that was not marketed as waterproof. So they balked, and Activent finally went away (it's still sold as one of several Windstopper fabrics in the Gore line, but has essentially vanished, which is a shame).
Currently, MSR is grappling with bringing the price down on its proposed "capillary technology stove," which is an integrated stove, fuel tank, and pot that weighs about a pound. MSR at first thought that when it hit the market in the next year or so it would sell for $170, but they got told by retailers that was never going to fly, so they're trying to hack away at that dollar figure.
Otherwise, anything you can do well for less than $100 will sell like hotcakes. Just look at Marmot and its Precip Jacket—it's a pretty-good rain piece that sells for $99 and can hardly be kept on the shelves.
Read Outside's 2004 Buyer's Guide for a look at the gear world's "Killer Values" and "Gear of the Year".