In our culture, from an early, highly suggestible age, we're bombarded by powerful ads created by psychologists who know every persuasive, manipulative trick in the book. We're methodically, mercilessly conditioned to never be satisfied with what we have—to continually crave novelty; to always want more, more, more.
So it's no surprise most of us have deep emotional "needs" (i.e. compulsions) to own every pretty thing we see—even something as inherently ridiculous as fancy keyboard buttons (a set, or even just one) that cost more than a whole keyboard.
To try to answer the OP's question: Depending on the effectiveness of the brainwashing programming you've received as a consumer, you may have to go ahead and buy everything you want, then let it sit around for while, before you understand hat the desire to buy it was what motivated you, not the desire to own it. Once you've bought it, it's just more stuff.
Ever have a friend or relative who planned to marry someone that you and everyone else knew was no good for them, and that such a marriage was doomed to fail? It would've been futile trying to talk them out of it; they had to go through the process to see that it was the idea of being married that they were in love with.
That's how it is with buying stuff. If you're lucky, you eventually realize how suggestible you are when it comes to buying all kinds of stuff, not just something as specific as variations on the same keyboards.
As an artist, I admire beauty and creativity. But to me, a keyboard is first and foremost a writing tool, and how it feels and responds to my particular touch is far more important than how it looks. The very idea of keyboards that light up in pretty colours seems ludicrous to me—the idea is to focus on your writing, not to look at the thing you're writing with. Would you stare at a pen you were using? Why? (That said, I wouldn't be surprised if they were making multi-colour LED-encrusted pens now, too... People will buy anything that's flashy and pretty enough.)
If you want to take a big shortcut, just keep 2 or 3 boards you really enjoy typing and/or gaming on, and consider everything else an addiction you've chosen to transcend. That's my advice—but of course whether to take it or not is up to you.
