I'm a big fan of Pulze. I think it's price is fair at €50/year (I think?).
It is limited in some capacity, and isn't yet fully loaded as it's still quite new. I'm beginning to have good discussions with the creators and they're somewhat responsive (but nothing compared to the amazing responsiveness of corona!).
I'm sure vexus is a good alternative, but from the preview it looked awfully complicated, but I may be wrong from the comments above.
I'd recommend Pulze. I came to it having not used any other similar plug-ins and only working in Corona+Max for a year or so, but it's still dramatically improved my workflow and I use it every day.