I too wonder about the super high cost of them which I encountered when assisting my M-I-L.
Sharper Image sells a disposable or two (one is prescription only) for far less than the amount you mentioned, This is a very small unit that fits in the ear but it is not a "Concealed" type.
And there are other companies that make low cost as well.
The more expensive ones (Including to a lesser extend the Sharper Image) have digital signal processing, they can be "Custom Tailored" by your audiologist to assist only on frequencies you need assistance on, in some cases they may have several equalization bands.. Some of them can distinguish to some extent between voice and noise and diminish the background.. And all this ability adds up.
But the thousands of dollars they charge is pure rip off in my book.
This is like the cost of meds.. Some drugs you pay as much as say 200 dollars for a month's supply.. Go to another country and pay 50 for the identical drug, made in the same factory, and from the same lot code.
Congress has given it issue lip service, but as of yet taken no real action, Even "Obamacare" And "Romney care" (Obama care is a much wordier version of the MA. Affordable health care act.) does not address this issue.
Some insurance companies are working on it though, after all, it is THEIR money they are saving.
Home is where I park it!