Don' t know much about Dogtra. You can find Innotek collar on Ebay brand new for about $50-75 less than you can get one from a catalog or store. Also petsafe has a new model called the Sport Dog (
www.sportdog.net ) that has a 2 mile range and is priced at $200. I have been thinking about getting one for my beagles. What I like about the Dogtra, Sport Dog, and some of the Innotek collars is that they are compact. Seem to fit a smaller dog better. Some of those other collars are huge.
Good luck.