For someone who don't already own a good one, that is a real drawback for that approach if that's what you are alluding to..

I would say for brand new, you can get buy with the entry level ones, say $300-$399 at Costco if you only play PCM files up to sampling rate of 192 kHz using foobar and others that are freeware.
If you want to be able to play higher sampling rate files and/or DSD files then budget for around $499 minimum. Mac laptops are better because then you don't need to worry about drivers. It seems that all, or almost all external DACs will work with iOS without having to download specific drivers, and iTune is free. Macs are expensive though.