Trade-off Triangles

It seems there are many places where we can encounter trade-off triangles. This is the simple idea is that somethings are characterized by three desirable attributes. And that you may select for only two of the three.

For instance:

• Rennovations can be high quality, performed quickly, or inexpensive.
  
• Security systems can be high security, convienient, or inexpensive.

I'm sure I've seen other examples of this in the past.