I have a new small Sebenza, and think it's great! It really is exceptionally well built--better than many customs I have seen. Is it worth the money? That's like asking if it's worth getting married or not, or getting a higher salary at the expense of vacation time. What's right for Ted may not be right for Frank (if there are any Teds or Franks on this thread, I'm not talking about you specifically

).
It's worth it for me, simply because I am a knife enthusiast, and find joy in fine craftsmanship. I'm not going to carry it every day, simply because I have other knives that I also really like and they will not stop having their days in the sun. I don't NEED it by any stretch--as Will P. (and others have) said, all you really need is a piece of sharpened steel. I find some wisdom in that statement. Wisdom in that not I, nor anyone else, can argue that the Sebenza will cut open your mail any faster than your Benchmade, nor say that "the guy in the burning building would have gotten out if only he'd had a Sebbie and not that Cold Steel." You can get the same steel, expertly treated, for less money elsewhere.
On the other hand, though, as much as many here often try to seem very nonchalant regarding knives, so as to seem like hard-working veterans of knifedom who keep it real and think of them as tools to use and don't get wrapped up in all the silly stuff---------look at how we spend our time! Every one of us, no matter what type of knife we like or what our economic situation allows us to get, obviously has some regard higher than 'simply a tool' for his/her knives because we're here spending time discussing them. How many of us have visited Shovelforums in the past month? Some of us have thousands upon thousands of posts, representing what many would consider to be an obscene amount of hours on the internet, which could have been used making ourselves smarter and richer. For members here who've posted anything more than a few theads of questions, I'm afraid you can't deny that you're a hobbyist, and you spend more time (and probably money) on these simple tools than really makes sense in the real world.
Therefore, I don't think trying to justify our sebenzas makes much sense. There isn't an absolute necessity for them, any more than there is for expensive wine or better than average sound systems. We have them because we like them. That said, having them because we like them is more than enough reason all on its own, so feeling like we NEED to justify them doesn't make much sense either. If you like your Spydercos, get them. If you like Sebbies, get them. If you find romance in the brute simplicity of a Sears box cutter, then by all means use that! Such choice and freedom to do as we will with our cash is the beauty of a non-communist system.
We can give advice, share our experiences, heap praise and lay blame when needed, but I don't think I have any more right to say anyone is a fool to spend their money on ____ than to say that their wife is ugly. In both cases, I would certainly deserve a swift kick in the ass.