There’s newer versions now, so I picked them up relatively cheaply but I have Elite Arion Smart B+ the advantage being you don’t have to manually vary the resistance.
ELITE Arion Digital Smart B+ Rollers: Unboxing, Build, Ride Details - YouTube
For TT warm up I also use the Feedback sports resistance rollers. I’ve only done a couple of different warm up workouts on them but I reckon they’d be good for most workouts unless you are putting out 1000w sprints.
Feedback Sports Omnium Portable Trainer (Bicycle Trainer) - YouTube