I think a Mola Mola Kula would be a gold standard here, but list is a bit over your budget. With an onboard Tambaqui DAC you are getting a world class DAC in a one box design.
I wold also look at a used Boulder 866 with DAC option installed.
these seem to go for around 1- -11k
And as a great value, the Moon ACE all in one is highly regarded, albeit a bit low on amps:
https://simaudio.com/en/product/ace-all-in-one-music-player/Would be fine with efficient bookshelf speakers.
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