How do you decide what your next upgrade will be?

As "audiophiles" or "audio enthusiasts", I think most of us are constantly on the hunt for our next upgrade to take their system to the "next level". How do you prioritize what your next upgrade will be?

I typically focus on what my weakest link in my system at the time is and choose my next upgrade based on that. But I know some people may upgrade based on "best bang for buck" or maybe other ways. How do you decide?

I have found myself at a crossroads trying to figure out my next upgrade. Right now I believe my DAC is my weakest link (by a long shot). I currently stream from my computer through tidal into a dragonfly cobalt into a Raven nighthawk. My phono preamp is also lacking. I have a VPI scout Aries with a Soundsmith MIMC star going into a Vincent pho-701. I recently purchased two Rythmik f12se subwoofers and I have no speaker isolation at all (isolation could be a potential upgrade). I have also thought about how fun it would be to roll some tubes through my Raven Nighthawk. There are so many possibilities. 
 

With all the upgrades we have to choose from how do you decide what would be most beneficial to your system?