I'm with @mrteeves
The only good reason for cutting back on speakers cost is in very small rooms where big speakers don't work well and small speakers are necessarily much cheaper.
Don't ignore the cost of room treatments. These can be just as important as speakers and closely intertwined. The cost of both should be lumped together as a proportion of system cost and in my view should be 35-40%, except in a very small room.
Front ends are often under budgeted too, except for often large expenditure on a DAC. DA conversion is the bugbear of digital audio, the problems may never be solved, so for the digital addict perhaps 15-20% of system cost is not excessive in the vain search to turn digital slices into holistic analogue reality.
For vinyl enthusiasts there can be good reason to spend 35-40% of budget on the front end, comprising as it does turntable, arm, cartridge and phono amp. And perhaps record cleaner.
All in all, this leaves no more than 30% for pre and power amps. That may be plenty. It has often been said that transducers are the most difficult components to get right.
And for 'tweeks' and snake oil? 0% please.