The value of a high quality underwater wide angle lens is hard to compare price wise to a standard UW lens. The value is only appreciated if you are shooting big subjects like wrecks, sharks, rays, schools of fish, whale sharks, etc.
Lens' like the Fathoms are super expensive, but sharp corner to corner, 100% zoom through and with their 110+ degree coverage, let you see the whole subject with the cam close in. This gives a much sharper/clearer picture due to less water between the subject and the camcorder.
I used a 120 deg Fathoms lens for all my Galapagos video. It's not the same exact lens as for the Stingray, but will give you and idea of the quality of Fathoms lens in general. At the same distance, a 65 degree lense has about 1/2 the coverage. One of the things that makes a wide angle shot is scale reference. Having a diver in the frame let's the viewer see the scale of the subject and that's when a super wide angle lens is needed.
One thing to consider about these expensive super wide angle lenses is the science and expense of the lens. Typical camcorders lens has about 45 degrees of coverage topside. Underwater takes away about 20%. So to go from under 40 degrees of coverage to over 110 degrees, with minimal distortion, with 100% zoom through and do it underwater, the 2k+ price tag is easier to understand. Key question is if the subjects you are shooting really need a super wide angle and of course, if you have the $$.
In the Caribbean, I would only consider a super wide for wrecks, stingray city or shark dives.