You can spend anything from a few hundred to tens of thousands…
I’d recommend a Roon Ready DAC connected via ethernet … but there are other options.
Checkout this topic for inspiration…
If you’re also interested in getting the best from MQA sources (eg Tidal Masters) this topic may be of interest.
The important thing is to have a DAC that’s in proportion with the other components in the system … ie no point having a top flight DAC if it’s connected to a mediocre amp and a pair of ear buds.
If you list your system maybe some of the others on here could point you in the right direction.