The type of jump rope you choose can certainly help with double-unders. There are plenty of jump ropes online that spin slow and make anything but single-unders difficult.
But for your own use, I really would only recommend buying a speed rope. I would recommend any RPM jump rope or any of these speed ropes (make sure it says “speed” rope).
But buying a $50+ rope won’t help you get your first double-under. Instead, it will turn 20 double-unders in a workout to something more like 80.
In basketball, that would be like buying a new ball in order to become a better shooter. Although the ball might help with minor details of your shot, you should be able to make free-throws with any ball.
If you are in need of some drills to get better at double-unders, use this resource:
Efficiency Tips For Double-Unders.
If you’re needing to properly size and fit your new rope, I put together this video for you:
And lastly, just because it’s fun to vary things, I put together this video for you in order to improve double-unders with heavy and drag ropes.