Adrian, there is no way to really answer that question. I have a McCafferty dulcimer and love it. Obviously, it was worth it to me. But I don't know how anyone can quantify the variables that add value to a dulcimer. Sound is one issue. So is comfort. And the visual appeal might be another factor.
My advice would be that if you have to ask if it's worth it, you should probably play for a while before making an investment in your dream dulcimer. With a McCafferty dulcimer you are paying for some variables that might not be important to you. Do you want an ebony overlay on the fretboard? That adds significant cost. Do you want an internal pickup? Do you want a radiused fretboard? Those options probably amount to a third or so of the cost of the instrument. If you don't want those, then you should not buy a dulcimer with them. If you don't know if you want those options, then wait.
It took me several years of playing to determine my own preferences. If you are a beginner or have only played a couple of dulcimers, I would suggest not even thinking about spending more than a few hundred dollars for a dulcimer until you have played long enough to know exactly what you want. (That is, unless you have loads of cash. If you have loads of cash, go ahead and buy a McCafferty. In fact, buy two, and send me one! And I'll take a David Beede dulcimer, too, while you're at it.
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Seriously, though, there is no rush. Attend some dulcimer festivals and pay attention to the dulcimers that sound good to you. Ask if you can try them. You will have the opportunity to try some nice dulcimers and you'll have a better sense of how they differ, what your personal preferences are, and what dulcimers might be best for you.
And don't forget to check the For Sale forum here. McCafferty has sold a lot of dulcimers over the past couple of years. I bet we start seeing a few used.

Yesterday alone I played three different dulcimers and two different guitars.
Working on the railroad, dollar and a dime a day/Give my woman the dollar, and throw the dime away