I personally believe that your font choice in any given layout is but one vital part of good design. I have invested a fair sum in fonts over the years, primarily to give me a competitive edge over the competition from a design standpoint. One other added benefit to having a unique collection of fonts in your arsenal is that it helps you prevent the competition from easily copying your work. If they get the chance take a client from you, then let them work harder for it, assuming they're even capable, or make them pay for the font which negates the chance for them to copy your work and do it cheaper to undercut your price.
Even if you only have a limited number of fonts, it's still possible to design nice work. Take for example Helvetica. It's been around forever, it's pretty boring but with the other necessary design skills you need, you can still create a good looking sign when you understand the impact that color, negative and positive space, and compositional relationships all play on a successful design. Having any font, be it a good one or bad one will not guarantee that you will be able to design a good logo or sign.
Here's an exercise I did several years ago that illustrates what I'm talking about. Using "only" Helvetica, I came up with several different layouts using one font alone. It illustrates that many other things come into play when you are working on a design project.
So don't put all your stock in fonts. They are not a magic bullet but rather, one of many tricks you must have in your bag.