The chiropractor 12W K-laser is about 22K. They are coming out with a 15W that has 4 wavelengths, very cool. I believe this will be closer to 28K.
One thing I found when looking around is that the class IV lasers all pretty much fell into the same price range depending on power. For a chiropractor, it was clear that some companies provide a lot more for the given power. The things to look for are additional wavelengths, ability to customize a treatment protocol with pulsed wave emission (different frequencies and super-pulsing options), company support and training, and warranty.
I don’t have a reference handy for treating neuropathy. I will try to find one for you. In the mean time…
A reasonable protocol for nerve regeneration would be a combination of continuous wave and pulsed at 700-2500hz. This will be good for general photobiomodulation to regenerate nerves. If there is a lot of pain you could throw in some pulsed at 0-100hz, which is most effective for pain reduction (I think one study used 2hz and was effective). Treat the entire path of the nerve from root to distal end using appropriate power depending on location and depth of nerve.