My first knife was a Benchmade Eclipse. After that knife, I thought I would never buy a more expensive knife because the Eclipse was so perfect! A few weeks later, I found out that AFCK from Benchmade was actually a lot smoother, and I love how I can flick it open with ease. Of course, as fate turned out, I was introduced to Microtech knives a few weeks after that. The rest is just plain financial depression. I still carry my AFCK, because I could never force myself to use a Damascus mini SOCOM or a two tone Halo or a dual action SOCOM...
So basically, I thought my upper limit was about $50, but it ended up around the $800 range, and I definitely see signs that it will go up... Woe with me!!!