I think dedicated network players are going the way of the Dodo, just as dedicated wordprocessors once did (remember those?). After all, each time a new service is introduced, either the service provider or the player manufacturer will have to develop a new app, and that for many services and many players. The same was true for smart tv’s or disc players with streaming abilities. It is just not a viable business model, and as a user you are stuck in a dead end street.
The alternative is either using a pc of one kind or another, with its universal browser (the Raspberry Pi is very popular for this, but any laptop will be just fine), or streamers by market leaders like Google (Chromecast) or Apple (Airport Express). The beauty of these units is that they have such a massive market penetration that no streaming servce can afford not to develop an app for them, and you can connect them to your existing high end stereo system. Both the Chromecast and the Airport Express have good internal DACs that will not be out of place in pretty good systems, but if you want something better they also have digital outputs.
See here for a test of the Chromecast:
http://archimago.blogspot.nl/2016/02/measurements-google-chromecast-audio.htmlhttp://archimago.blogspot.nl/2016/02/measurements-google-chromecast-audio_27.htmlAnd here for one of the Airport Express:
http://www.kenrockwell.com/apple/airport-express-audio-quality-2014.htmI prefer the Chromecast because once it is connected it no longer needs your smartphone, saving its battery. It can handle 24/96 files, and with BubbleUPnP it can also connect to a hard drive on a computer.
And the good news is that they cost next to nothing, so you can experiment without investing serious money.
Of course there are plenty of good modern amplifiers to choose from, also with inbuilt DACs. Even a cheap 2x100 watt Yamaha RN 803d receiver with digital inputs, Airplay and dlna is perfectly fine for anything other than inefficient speakers in large rooms. It even has a room eq system built in. There are now quite a few DACs with variable output (e.g. Pioneer U-05, Marantz HD DAC1, Benchmark DAC3, to name just a few that are more or less in your price bracket). Alternatively, and if you like playing audio and video discs, the Oppo UDP 205 4k disc player can also serve as a first rate pre amplifier with digital inputs for e.g. a Chromecast, and inbuilt high quaity DAC. Add a beefy power amplifier and you are done. The Benchmark AHB2 measures exceptionally well, with exceptionally low noise and distortion, but even a cheap 2x350 watt Yamaha P3500s pro audio amplifier is as good as many audiophile products:
http://www.homecinema-fr.com/forum/amplificateurs-de-puissance-haute-fidelite/mesures-ampli-yamaha-p3500s-mise-a-jour-t30056383.html I recently bought the 2x250 watt P2500s for my son, and I cannot be happier.