Thank you. That's an interesting solution; it's an interesting direction to explore. The equipment you suggest costs about $450, over twice the money I want to spend. But I get the idea.
Unfortunately, it depends very much on the country/continent in which you buy.
You can get the Q Acoustics 3010 used in the EU as a pair for around €100, sometimes less. Alternatively, you could also take Heco Victa 200/201/202, which can be obtained cheaply both used and new. But there are comparable speakers from Dali, Wharfedale, etc.
Active monitors, e.g. the Mackie CR4-X, you can get (with a defective active part) from recycling and remainder dealers, e.g. on Ebay or used via classified ads, approx. € 50.00.
Devectives Mackie CR4-X
There are few alternatives to the SMSL DA-8s if you prefer balanced inputs. If you can do without balanced inputs, remote control and a perfect volume control, then you could also use amplifiers like SMSL A12 or SABAJ A1, or without Bluetooth also AIYIMA A8 or AIYIMA A07, all under 100 €.
Addendum: SMSL A100 Amplifier Class D Infineon MA12070 Bluetooth 5.0 2x80W 4 Ohm