Well I think part of your problem might have been the type of knife you buy. For one thing if you buy a knife from a flyfishing compnay that lists its materials just as "the best available", that would concern me. What does that mean?
Also MOP is a tricky little devil. I made a kit knife with MOP scales like a year ago, and the scales alone ran me about $100 for top quality stuff. Even that started to just break apart when I got sloppy and tried rushing things. Using cheaper peral and the results are even worse. Not trying to defend anyone here, or place blame either. Just that before buying you really need to do some research. Does the maker or manufacturer have a good reputation for making a fine knife? Is the maker up and coming, and then just possibly producing a slightly lower quality knife at a lower price? Also is it meant as a working knife or a collectors knife?
You need to keep in mind that a knife is primeraly a tool, and thus meant to be used. To me some small cosmetic flaws in a working knife are no big deal. I know that in using the knife I will be using it and just adding scratches, dings, etc. So as long as it isn't a huge flaw that inhibits the use of the knife I wouldn't really care. Another thing I would consider is custom vs. production. If it is an expensive custom knife, and the maker offeres to fix it if I am not happy it is no big deal.
The biggest thing here is that just about anyone who wants to can start maing and selling knives. A knife is a fairly simple thing, especially when compared to a watch. And while I agree that the Sebenza is a fine knife I also think that there are many fine custom makers out there that will produce knives of like quality, except offering many different options.