My opinion is to buy the Garmin and a radio collar in the 217.xxx range. If something goes wrong with the Garmin, you still have time to locate the dog with the radio collar. Just post up a message on ETHD that you need help tracking a dog in your area and I am sure someone would come help out. You should probably be able to get a radio collar for less than $100.00. Or if you want, I have a Tracker Intello collar that needs to be sent in for service. You can have the radio collar for free, and it will probably cost you 50 bucks or so to have it serviced.
PM me if you are interested in the radio collar.
does the 217 freq have an advantage over 216/219/220/221?