Well, the Lumin is 4 times the price of the Bluesound, so if there is anything to the saying "you get what you pay for", it should sound better. And of course, looking down the line, when a better streamer comes out for the same price as the Lumin you will loose 4 times as much on its resale.
I get what you are saying. But when is the last time you paid twice as much for an audio doohickey and got a 50% improvement. I really don't think most 10K speakers sound twice as good as 5K speakers, all things considered. But as audiophiles we tend to pay a lot for incremental improvements. To my ears, the Lumin sounded good enough to shell out the $$. YMMV.......
Oz