I have the elite Turbo Muin smart b+ trainer, it was on offer last month at halfrauds for £290. Bought a cassette and QR skewer so in all about £340.
As already pointed out this is not a “smart” trainer in essence, (that’s the REAL Turbo Muin with resistance controlled by zwift) but rather a turbo trainer with a speed and cadence sensor built in it which, ironically, you have to set up on zwift as a power source! It connects via ANT+ or BLE. However, the power readings are woefully inaccurate at higher cadences. I have proven this by buying a real power meter since.
But it is a great bit of kit and so quiet. The resistance levels are more than adequate too so I just use my gears and I can rarely get into the large chainring!
I guess it depends on what you want out of a trainer really but zwift will work with almost any
trainer with a speed and cadence sensor.