Got one this fall. It's awesome. If you don't go the DIY route, get the plan from the provider where they automatically mail you batteries every so often. It triggers your dumbass memory to change the batteries.
Also, ask for a second set of batteries up front and change them about 50% of the way through what they tell you the battery life is. one of my dogs burnt through the battery in like 6 weeks because she was challenging the fence very often in the training phase(sound that goes off before they turn the shock on).
My dog has gotten out three times. All three were due to batteries being out.
I love it because it is super nice not having a fence now. Easier to mow/maintain by not having a Fake Sugar Dick (WARNING, NOT THE REAL SUGAR DICK!) amt of trimming and looks better imo.
Also, my other dog is a hound(known for being very stubborn) and she was trained instantly upon receiving her first shock.
Also, don't worry about some ppl saying this is cruel. I shocked my forearm before buying the thing and it feels basically they same as putting a 9v battery on your tongue. Its enough to surprise you, but not hurt at all.