If you want to know how much to charge for a bow work out how much the materials are, labour, tools machinery, general insurance(fire, theft etc), rental/ workshop space, electricity, council rates for running a business, advertising, miscellaneous overheads, paperwork, taxes.
Sure there are guys selling bows but I don't think there are many people relying on it for a full time income as they would go out of business in a heartbeat. Their business model just doesn't add up, wouldn't even allow them to break even, let alone make a profit. Most guys are using their regular job(or are retired) to subsidise their bowmaking. This results in people being accustomed to unfeasibly low priced bows, with great finishes, great performance and top materials. Totally unsustainable.
Mix this in with a lot of very low level bowyers flogging bows on ebay for little more than the price of materials(the occasional one is actually a very talented bowyer, but still insists on undercharging just to get a bit of cash in the hand right now), the general person gets the idea that a bow should be cheap, and is not worth much money.
The $400-600 for a well made osage bow has been the same for the last 19 years that I have been involved in the craft. Back then a full length osage stave(seasoned but with bark on) retailed for $ 65-$120, then add shipping. Now 20 odd years on, with ebay you can get an osage bowstave, with a lot of work already done, taken down to one growth ring, for $20-$60.
The very nature of making wood bows, at the top end of the spectrum means that so much skill and time is in the tillering, quality of materials. They are factors that are not suited well to methods of mass production, and high volume turnover in sales with a small margin for profit( how most manufacturers plan).
There is no shortage of talented bowyers. If I wasn't a bowyer myself I would have no hesitation in buying a bow off them(I actually do occasionally, either because of admiration of their individual talent, or just to see how my own work stacks up). I have also observed that many talented bowyers that try to make a go of it professionally stop making bows for sale after a year or two.