The cost of specialised hifi stereo music streamers, aka network audio players (such as Cambridge Audio's NP30), is mostly down to the build and sound quality of their components, especially their built in digital to analogue converters (DACs). One of their main functions is as a CD player substitute, so if you are replacing a good quality CD player originally connected to a similarly sounding stereo amplifier, you should really be looking for a box of similar quality. Otherwise you are in danger of being stuck with a rather poor sounding streaming solution, mostly due to the streamer's poor quality DAC circuitry. The solution would then be to later get a good SQ stand alone stereo DAC unit to place between the poor SQ streamer and good SQ stereo amplifier, which would cost around the same sort of the price that a network audio player would have cost in the first place!
All network audio players come with a built in display and most can be controlled by their own free Android & Apple iOS apps in addition to the remote control. Some have USB ports to allow the selection and playback of music media stored in USB memory sticks or even external HDDs and all have other music streaming functions, such as internet radio. The network available stored music played on them can also be controlled by third party DLNA controller applications (such as the popular BubbleUPnP app for Android), the prerequisite being that there is also be a DLNA server running on the network, to deliver the media from a NAS or other media storage device.
Street / internet prices of new devices start from around $300 upwards and what you should be comparing them to is the price of replacing a CD player and how you'd go about selecting a new one in terms of cost versus quality. Examples of popular network audio players include, in the ~ $300 - $1500 price range:
Cambridge Audio Sonata NP30
Cambridge Audio Stream Magic 6
The Stream Magic 6 and the Pioneer N-50 even have a DAC USB port that allows their excellent SQ internal DACs to be used directly by a computer running music playback software, swapping out the computer's usually poor SQ internal / sound card DACs, by connecting with a USB cable.