I think that it really doesn't make sense to reduce the purchase of speakers to some formula. We all know that paying a little or a lot for speakers is absolutely no guarantee of quality or that you wil ultimately be happy with the purchase. I would say that you want to get the speakers which please you the most and which match the equipment you already have while still allowing you to stay within your budget. That said, this is still a very difficult task in practice, but why make it even more difficult? If your total audio budget were say $50,000, would that say that you have to buy a speaker for $15,000 $20,000 or $25,000? Why? Especially if you can find a speaker for $4000 that sounds as good or better? I agree with Eldragon that while speakers are very important, pay close attention to the preamp. That is where in many systems good sound is turned into bad. I personally don't like the idea of spending megabucks on speakers since at any price point, these are the most "flawed". And raising the price point doesn't necessariyly get you a less flawed product.