If you have the tension on the wrench just right, I have been able to open a padlock with one squeeze. More often it takes 3 or for quick pops of the handle, but this is pretty easy.
This gun is high quality and very sturdily built. I think it is well worth the cost.
I got mine from lockpickworld, it was $44.99 and you can follow the link.
It takes some practice, but in under 30 minutes of playing Julian and I were able to both consistently open practice padlocks. That was with sharing the same gun.