There are a number of things commenters here seem not to know about the hearing aid racket. I have a profound hearing loss and have been wearing hearing aids for most of a decade now, let me fill you in on just a few of the things I have learned.
For all of you championing some sort of cheap or build it yourself aid - unless you have a very light hearing loss, forget that. I once thought the same thing, and tried a number of them, and found that they're basically crap. Just amplifying all sound that hits the microphone doesn't work well at all. A door slamming or a dish clinking can be VERY PAINFUL if overamplified, even if a person without hearing loss barely notices them. After this consideration, there's the problem of the sounds you want to hear being buried under a bunch of sounds that are present but not bothersome in daily life: cars driving by, computer and HVAC fans running, refrigerators humming, crowd noises, air and hair moving over the microphones, and so on.
I'm not an audiologist or in any way connected to the industry other than as a customer, but what I've learned over the years from wearing high- and low-end hearing aids (I have one pair that cost almost $7000) is, human hearing is far more complex than most people realize. Most folks out there swim in a sea of sound that they are well attuned to, but like a fish, give little thought to the navigation of. It just works, like magic. When your hearing starts breaking down, though, it's an incredibly hard problem to selectively amplify the sounds you want to hear in the many situations you will encounter throughout the day. In a crowded room you want to 'focus' your ears on the person in front of you; in the kitchen you want to be able to hear several people who may be moving around as they speak yet filter out extraneous noise like the bacon frying in the pan, the refrigerator hum, the fan over the stove, the dishes rattling around. A healthy ear does all this effortlessly; hearing aids are only now getting enough processing power to do it maybe half as well.
I cannot stress this enough, by the way. NO hearing aid will bring your hearing back to what it was. At their BEST, hearing aids are about as good as a cheap car radio tuning a weak station. If you don't need hearing aids now, protect your hearing, because losing it sucks in about a jillion ways.
In the US, most insurance plans do NOT cover hearing aids. The VA does, and they are the number one hearing aid dispenser in the country. Costco is #2 and they don't even bother handling insurance claims for the patient - he will have to do the insurance paperwork on his own. (I know; I'm wearing a new $3k pair of Costco aids right now and am lucky to be one of the few in my area with a plan that covers part of the cost.)
Many if not most states have laws which require the hearing aid dispenser to take back the aids and provide a full refund with no questions asked within 30-60 days of first receiving them. And when that happens, that set of aids can't be re-sold unless (at minimum) they go back to the factory to be completely rebuilt. This creates a number of people who will comparison shop by wearing multiple aids for most of the trial period, then returning them. In their defense, that's about the only way to know if a hearing aid and audiologist/fitter work well for a person. But even so, this creates a lot of wasted time and investment for audiologists and fitters. They have to make up the loss somehow.
Usually the price of the hearing aids includes months or years of followup visits to the audiologist or fitter. And if you wear hearing aids, you'll need them. Everyone has a different hearing loss and everyone has a different set of situations they need to hear well in. So the audie/fitter will need to make a number of adjustments during the lifetime of your hearing aids. Additionally the aids are subject to a lot of moisture and earwax (your ear canal is actually a pretty disgusting place) so the audie/fitter will have to clean and recondition the aids more often than one might initially suppose. Behind the ear hearing aids? They'll get wet from rain and sweat.
There are companies like America Hears who will sell you good-quality hearing aids via mail order, and give you a gadget to hook them to your computer and perform adjustments yourself. It's not a bad way to go for techie types, but be warned, there is a lot of specialized knowledge involved. More than you'd think - this isn't as simple as playing with the equalizer on your stereo. In the two years I wore such aids, I never got them to work as well as my current aids. But mail order hearing aids are no longer an option for me - some audiologists in my state got together, testified before my state congress, and had that mode of sales outlawed.
I am in no way trying to justify high prices of hearing aids. I sure wish they cost less! All I've been doing is laying out a few of the obstacles present on today's landscape. As more people suffer hearing damage (and they do in today's urban environments) the market will grow, and the prices will (hopefully) go down.
But today, if you want good hearing aids, be prepared to pay $2000 or more. (This is the US-centric view, I dunno how it's done in other countries.)