How much do you have to spend?

Wondering whether putting out another $10k would result in significant audible improvements…

A definite YES! 10k would likely help most of us.

+1 amplifier is weak link, maybe DAC the next

@fritzenheimer

For half the price of the Reference 1 Metas you can have the R7 Meta floorstanders. I went there from LS50’s and it’s a definite upgrade. Not sure but I think the price difference reflects where they’re made. The R7’s are first rate although it looks like they may not have the cool silver ones anymore.

@fritzenheimer

I run the same subs also.

Less than you think. ;-)

Don’t think you can answer the question this way; starting out with money.  Music satisfaction is the goal, not budget.  How much you end up spending usually depends on what is pulling at your heart strings at that moment, be it amp or source or cables.  
A pragmatic approach is to start out with the biggest variable, speakers.  We all love something different, new or used.  Having found the speakers, we now look for an amplifier with the matching characteristics needed to drive our chosen speakers. Cables to hook them up and on to preamps and sources.  Eventually we have a system, understanding we’ve some errors and corrected along the way.  Then and only then can you add it up.