I very recently got my first Sebenza. In fact, when I first saw it & handled it, I was NOT impressed. I thought, "Man, I need to get my mini-Skirmish back." But after playing with it for a day or two, the nice things about the Seb came out.
Now, is it worth 2-3 times the money of a MS? That's entirely up to you. I heard & read about some saying a Seb is a Bradley Alias, made by Benchmade, no less. But really, a an Alias is a Seb copy & like the MS, isn't quite the quality as the Seb.
As to worth, it depends. If you NEED that $350-400+ to live off of, then no. But lets face it, a Seb (Or even a MS, Alias, etc.), are knife enthusiasts thing. Someone, just looking to get a pocket knife & not have a collection of knives (No matter how small it is), are going to spend the money for ANY of the listed knives.
You "average Joe" just is not going to spend more than a $100 or so. So, literally is it worth it? No, it's not.
But, I didn't spend the time & money that I have to buy/trade-up to just get a copy of something. I wanted to have THE knife, the one that everyone else is copying. People can say that I'm justifying my purchase/trade, but you can make a case that they're justifying why not to get a Seb.
The bottom line is, you & I don't NEED a Sebenza, mini-Skirmish, or a Bradley Alias, for that matter. All any of us NEEDS, is a decent quality folder. If people didn't spend money to get nicer ones with "extras", whether that's extra quality, extra features, or both, we'd all be using Buck 110s or something similar. But we don't, do we?
From what I understand, this type of question/thread happens every so often. Personally, this is the first one I've participated in. It has been interesting, though.