re: unruly dog
I'm not a fan of electric fences. Only (1) because I think regular fences are much safer for people AND the dogs... and (2) I've seen a couple that just don't work. So (1) -- I mean that if you have an electric fence set up in your yard... yes, your DOG might stay in its boundry, but people might not know that it will / they might walk onto your property and agitate the dog, or try and call the dog over to pet it and not understand why it's staying away. I've seen situations like this... or where someone complains because they think you're letting your dog just wander around outside without supervision. My (2) is that I've known two friends who have the electric fence and BOTH their dogs figured out VERY quickly that if you just run full blast at the line and experience that unpleasent shock/buzz for a moment, the sensor stops working (thankfully, because you don't want continous stimulation to hurt your dog) once your dog passes the barrier, and then they're home free. I've seen this with my own eyes as my friend was shocked (and thought it was pretty amusing) that her dog figured out so quickly that he could just run through, steel himself to the unpleasent sensation, and then be FREE!
My suggestion is this: training doesn't need to cost any money. There are very simple obedience items that they can do on their dog without sending it to a class. One is leaving a leash on the dog for awhile. Let it drag around the leash, etc. (hopefully it's not bad enough that it chews it) -- this really helps quicker correction when you're training and is something many trainers tell you when you first get a rescue. So whenever the dog does something bad, you can quickly correct with a tug... or if it starts beelining for something, you have a leash at least that you can try to grab before it gets out of your reach.
A big training thing could also be teaching the dog "WAIT"... I use this for my dog at doors, etc. You can teach it inside... have it wait at any barrier. The best way to teach the dog WAIT is if you have a box it can stand on first, because then it's a PHYSICAL difference between the floor and the box. You can also teach it to wait using doorframes since those barriers are also easy to distinguish. Walk the dog towards the barrier, then say wait, and have the dog stop at the barrier, and then praise it and reward it. Have the dog wait in front of doors too, and once this gets imbued in its brain, I've been able to have my dog at a dog park, and seen her start galloping off somewhere, and I just yell out WAIT, and she stops suddenly, almost subconsciously ... and looks around for me. It can literally be a lifesaver if your dog is about to run across the street and there's a car coming, or if it's taking off if you drop the leash, or you're on a hike and it's about to go investigate a rattler or a prickly thornbush, etc.
Hope that helps!
Dogs think every day is Christmas - R. Bradbury