I have nothing against the Audioquest Cobalt DAC -- in fact I'm using one right now with my Macbook Pro to stream Qobuz and I like it very much for the limited way in which I use it. However, if you're looking to build a home system, you may want the flexibility of a DAC that has multiple types of inputs: optical, usb-b, HDMI, etc. The Cobalt has exactly one input and output, USB-A and 3.5mm stereo audio jack. The minute you add another digital source to your system (like, say, a TV with an optical output), you'll either have to use the DAC built into the TV or upgrade/purchase another DAC to handle the extra input. MQA complicates things slightly because you can get MQA decoding in very inexpensive products (like the Audioquest Cobalt or the Meridian Explorer 2) or more expensive products, but there seems to be little out there in the gap between the two. Taking MQA off the table as a requirement certainly opens the door to those middle-tier products that are between $300 and $2000.
If it were my money, I'd go for the Cobalt right now (as it sounds like it would cover all of your current digital needs) and as my digital sources grew, add a upper-entry-tier non-MQA DAC to handle other kinds of inputs (the Schiit Audio Bifrost 2 at $699 comes to mind).