What is proper ratio of money spent on amp/preamp/integrated vs speakers? 1:1?

For digital playback, I spend ~30% on source and DAC, another ~30% on speakers, and the remaining on preampfification, amplification, and cables. That ratio has served me well in multiple system setups. There's never been an obvious weak link. 

However, everyone has made good points about finding "your sound".  I recently violated my rules and acquired speakers that are only around ~10-15% of the stack cost. They were special to my ears and brain so, even if you adopt a ratio, you may end up violating it anyway down the road.

The common denominator here is, buy what works for you.

There is no “golden ratio”.  Blind test gear if you would rather know how something sounds without the bias of cost and gear reviews.  The results may surprise you and you’ll likely end up with a much more cost effective system. 

IIRC Robert Harley’s book “The Complete Guide to High-End Audio” has a suggested % allocation. BUT, it is only a very loose guide maybe more useful for a rough idea in a new audio chain.  Normally, one looks at their audio chain a then address the “weak links” to raise performance vs a simple $-% allocation .