2-3k budget - adding DAC/Server to Bluesound Node?

Upgrade your Node first. The Node can be improved by a good margin by upgrading the internal power supply with a PD Creative board - https://pd-cf.com/.../bluesound-node-2-2i-upgrade-low.../

I power this board with a SBooster LPS. Takes the node to a level that you would need to spend $$$ on to achieve. And as others have said, a better DAC will then keep you happy for a long time.

would the RME dac be a significant dac upgrade?

can it be used as a pre amp to drive my two channel power amp? (and then have the node attached also?)

I have a Cambridge CXNV2 streamer 

it’s great with Qobuz and a Rotel A14

the CXNV2 is v easy to use and I get firmware upgrade as easy as pie

also Cambridge has excellent and I mean excellent on line service

ive been down the road with super expensive gear and now that’s over!

BTWVgot the Cambridge for $525 for Cambridge online from CambridgeUSA

refurbished full factory warranty as well!

I'm continuing to evolve.  Currently use a NODE into a Mytek Manhattan II DAC.  Will likely upgrade NODE to an Innuos streamer once new models are launched.  

I'll tell you what I have (and like):

* sonicTransporter i9 (a music server running Roon and HQ Player)

* Matrix Audio Element X (an integrated streamer/DAC/preamp directly connected to my Benchmark AHB2 power amp)

The latter would have been within your budget (barely) when I bought it new, but the new Element X2 (with touch screen and HDMI) now is over $4K.  If you can find a new or used X1 within budget, it'd be worth considering. It uses one of the most advanced ESS Sabre DAC chips and FWIW does very well on ASR tests.

Good alternatives in its price range include other Matrix Audio,  HiFi Rose, NAD, Cambridge Audio, and Mytek products.  I doubt there is a big noticeable SQ difference among these, so the feature sets may be more relevant.  But some listeners may be hearing differences in sound stage, imaging, and bass response among similar products at this price level.