$30K DAC in a $70K system - wise or ridiculous?

One thing I'd recommend you consider would be to snag a really good power regenerator.

When PS Audio released their P15 unit, I upgraded from my then-current P10 model and immediately noticed significant improvements in the bass, the soundstage and the clarity in the mids to highs, on both my PS Audio DirectStream DAC and my Mytek Brooklyn DAC.

As to your idea of spending on improvements nearer to the source, I'm in agreement with that concept.

Rotel?!!!  April 1st is next year. 

I humbly suggest the OP also consider installing something like a Goal Zero Yeti lithium-ion battery generator as his power source. In my system such a device lowered my noise floor (I didn't even consider that I had a "noise floor" in my system, but once it's gone you can't un-hear it...). This would be (IMHO of course) appropriate cornerstone for any unleashing the true capabilities of the current system and any future upgrades.

Cantorgale you may have already made your mind up anyway I’ll toss my 2 cents in .
Sure sometimes it’s a good move to better your front end however with a budget of 20 grand for a dac I’m pretty sure with the fast moving advances in digital playback I would look elsewhere for lasting improvements in your system .

Myself I use a 1bit FPGA digital stack which keeps step with a manufacturers advances in sound quality ect via firmware updates making it future proof for “now”

However I like to think long term when dumping money for enjoyment in this hobby and recently purchased some lightly used Jeff Rolland amplifier’s and Rolland preamplifier .
 I could of easily bought a $20,000 digital front end instead however for long term investment I believe better electronics was way to go for me ,.that’s my 2 cents worth .