Percentage to spend on Amp and Speakers

Regardless of the budget set aside for one component or the other, if in the end they don't work at least reasonably well together the money wasn't spent proportionately. Don't let the money burn a hole in your pocket. Take time to audition enough equipment to develop some sense of the level of quality you want out of a system, then compare that to what you can afford to spend. Trelja speaks wisely. There are no absolutes except that system synergy is paramount and falling in love, true love, takes time. Finding pieces you love that work together takes even more time, but it's worth it. Now, to answer the question more directly, in my case (using retail prices as some components were purchased used) the ratio was equal amounts for amp, speakers, pre-amp, source and cables/accessories (not including acoustic treatments for the room). This was completely unintentional and YMMV.

Depends on the system and speakers. With really transparent and revealing speakers (like ribbons or full range esl's) it is easy and beneficial to spend much more on an amp (preferably 2 amps) and pre. This is not only rewarding but critical in this scenario. Not saying that source, interconnects and speaker wire are not important, but matching amps/pre with certain types of speakers is the most important link and makes all the difference in the listening experience.

Trejla has a good point. I think I took for granted that most people understand that some components do not work well with others. That is one of the many benefits of Audiogon. If you cannot audition recommended equipment you can at least ask opinions and find both arguments for and against certain purchases. Auditioning is, however, the best path to follow, but not always practical. I still maintain that the speaker should be the bulk of your investment. Other components can be upgraded as money becomes available. But if you don't concern yourself with what is actually reproducing the sound, you are putting the horse in front of the proverbial cart. I wouldn't get caught up in cables and interconnects. Buy good quality and you should be happy.

One does usually put the horse in front of the cart, proverbial or otherwise. As someone who just purchased new speakers (used, 1/3 retail), speakers I love and plan to have for many years, speakers I will upgrade around, I agree with Wsmatau that it wise not to, er, put the "cart before the horse." :-))

Whoops...lol