I bought a 2nd hand Schwinn, a decent German brand but nothing fancy in terms of connectivity, just a regular heavy flywheel and manual control. I paid €300.
To that i use power meter pedals which were any way on my road bike, i just swap them over for my midweek indoor rides and then back on the road bike for the WE.
In my mind i have what i need to follow my training programs on Training Peaks, easy dial in resistance and totally repeatable. My bike is set up in my office, i can jump on it and start a session in less than 5mins vs a Turbo that would need much more time and space, and of course a lot less dosh than a high end Wattbike or Pooton