Congratulations and good call on improving the source by switching to N200. Now if you bring a high quality DAC, you should be able to appreciate the nuances (or not) over your integrated DA2. I also like your approach of long term listening before forming any conclusions.
I believe the main issue with DAC costing 2x, 3x or 4x times is not whether they sound better or not. It’s the added cost that doesn’t quite commensurate with the perceivable differences in SQ. Most folks are quite content with a $1500 DAC that gets them close to 80-85% performance of a DAC’s costing, say $5K.