More money toward better speakers or a better DAC?

Sorry, my BDA served me well. All within a system that retailed at about $15K. 

I have speakers that sound right to me in a room meant for such speakers and treated the room to my liking.
My old DAC served me   A Bryston BDA -1.  The AM DAC improved the “air” around notes, added soundstage height and depth, and improved tonality. Resolution remained the same which was always good. 

I say it depends on what one has in one's system at the time of consideration.

In my case I was using a 10 year old DAC and had speakers that worked well in my room with my current amplifier. I wanted a new DAC, one that was NOS, R2R, and had tube output stage. Bought a Audio Mirror Tubadour III. It made a substantial improvement towards the experience I was looking for.  

It is more how long lasting  the qualities a DAC has to it’s owner. Not how long a DAC holds it’s place in the market. I held on to my BDA-1 for 8 years. Bought it used, sold it for 2/3rds what I paid for it. A highly regarded DAC that provides the sonics one desires should last a person well beyond 3-5 years. The market value is something else. 

I believe most would agree with you that the Bluesound Node does 'confines' the music and that it is the weak link in your system. Many have posted here that they use it with an outboard DAC.