I'm in the market for a basic smart trainer as well. Not sure if that's what you're looking for as well, but smart trainers allow the popular software like TrainerRoad, Zwift and Bkool etc. to adjust the resistance on your trainer to give it a realistic feel. So-called dumb trainers only have manual resistance changes.
Some 'affordable' smart trainers are:
- Elite Qubo Digital Smart B+
- Elite RealTour B+
- Tacx Vortex