Mrtennis,
I think your logic is somewhat askew. Just because you've heard expensive systems and they have not impressed you does not mean that there aren't thousands of systems out there that cost a lot less that would sound night and day better than your mini-system.
Probably, your mini has a nice basic midrange, with a hint of bass, and is not too offensive in other areas and to you, that's great. Many of us on this site wish we could be content with such a modest system, but the fact is, that I, and many others here cannot. And if I were a betting man, I'd bet that once you heard a system that walked all over what your mini is capable of (and there are many out there) you'd suddenly get that upgrade fever...
Heck, in fact, I have an old vintage retro system with Altec speakers, an Onkyo receiver and a Sony turntable with a Grado cartridge that I paid less than $200 for and I bet it will outperform your mini. It sounds really "good," to me, but as "good" as it sounds, my other more upscale systems sound appreciably better.