There are reasons to spend that much on that humidor - if you're a collector, if there is some meaning to it for you, if you're a huge Gurkha fan, etc. Now, that being said, *I* wouldn't pay that much. But I would pay a few thousand for some of the Elie Bleu humidors (if I had the money). Not because I think they are the world's best at storing cigars but because I really like their aesthetics.
However, you definitely want to have something like that appraised/evaluated. I can't tell from the picture if it would actually hold up to 500 cigars. However, I *do* know that Gurkha has an active social media presence and I've had some good interaction with them on Twitter.
If you're willing to pay $500 for the humidor if you can get its authenticity verified, then maybe start by sending a tweet to Gurkha, include the link, and ask if the claims are true (to begin with - like only made for dealers, how many signed, etc.) If they say that it's not true, then you just saved yourself $500.
No reason to go through all of that at all.. a simple google search reveals that this humidor was released just last year as an LE.. which is something that Gurkha does with quite a bit of frequency to be honest (theyre always releasing limited edition this, or special edition that... signed by so, and so, etc..etc..).. there isnt much of a market for fake humidors or fake K Han signatures.. the risk is extremely low here...
the larger concern is the asking price/value.. I am pretty sure that Han's signature isnt going to increase in value significantly over time (although I admit I am no expert).. and while this particular LE Humi isnt available "new" anymore.. it is still regularly available in the secondary market (again, google will show where its been sold on ebay, a motorcycle forum, and other places in the last 6 months..and sold for considerably less).. and its a pretty safe bet that there will be yet another "limited edition gurkha humidor" released sometime in the not so distant future....
so.. taking all of those things into consideration.. the question is.. is it worth even remotely what the asking price is..
to me (and I believe the vast majority of people out there).. its not even close..
If you individually are a rabid fan.. or just have to have it for some reason... maybe so..
But the chance of you ever being able to recoup your financial investment.. is likely very low... so it better be worth it on a personal level (again, huge K Han fan.. huge Gurk fan.. etc..)..