I have a Kershaw Leek, which while it isn't particularly expensive, is easily on the "cost exceeds direct utility" side of things, is easy to take apart, and I can't imagine what I would regularly take it apart for.
Kershaw leek is really a great knife.
Also keeping your pocket knife sharp is another example of it being directly maintainable and repairable. I often spend several hours a month sharpening my pocket knives though I probably have a few more than the average person.