I'm of the opinion that you should be able to find a good portable rig or desktop rig and spend less than $400 total on either one(not including a laptop). Mind you, I'm not saying the be all and end all of audio. I am saying a good listenable, comfortable system that you could be happy with for non-critical listening for a very long time. When you go above that price point you are either hunting a specific feature or you are headed into that diminishing returns territory.
(Desktop - Hifimediy DAC $50 - Magni 2 amp $100 - Sennheiser HD6xx $199)
(Portable - Cayin N3 $150 - Fiio A5 $100 + (Your choice of in ears - $150 buys a lot these days))
(Desktop - Hifimediy DAC $50 - Magni 2 amp $100 - Sennheiser HD6xx $199)
(Portable - Cayin N3 $150 - Fiio A5 $100 + (Your choice of in ears - $150 buys a lot these days))