I think that your speakers and amp should be considered as a single purchase for pure synergy. That combination will run 50-60% of total system budget. In my case the retail on my speakers is $15,000 and the amp is $10,000 and my system total value is about $50,000. These numbers seem to be about right in my case. I mention the amp and speakers together because it is so important to get the part right to get the most out of your speakers. Garbage in - garbage out. Every speaker designer has voiced their speakers using some type of amp and if you find out what works best the speakers will sound their best.
Perentage system $$ for speakers
While reading various posts in the past, I have read comments where some believe that the speakers should only be about 15% of the total system cost where other believe they should be the main focus. I am not looking for a right or wrong answer in this, I am just curious as to the thoughts of others on this topic.