Good lgd's are worth their weight in gold. Its just so hard to define "good". Its not brew specific. There are good and not good guardians in all ldg breeds.
I have known folks to give way good dogs because they simply don't have anything for them to guard any more. I have also known people to charge $4000 for a 4 yr old spayed female who was proven during birthings with lambs, kids, calves and poultry.
Its a fine line in trying to determine what your livestock is worth. And I personally think its a more difficult decision for people who have poultry only. Here's an analogy as to why... Many lgd's can be put immediately with sheep or goats from the time they are born and stay with them even through the teenage sillys. Poultry is different story. Mine are with poultry from the time they are born until sometime between 8-12 weeks old. They are put with larger livestock until they are close to a year old (maybe older) when they have a basic understanding of the difference between "play" and "prey". So... You own poultry... Rare poultry. Your hens would cost you $60 each to replace. How many hens would you have to have killed to justify a $1500 dog? Quite a few. But say you have sheep... Nice sheep. Each ewe is worth $3000. See where this is going? Preventing the loss of one $3000 ewe makes the $1500 dog quickly justifiable. However, it would take a lot of $60 hens to justify that expense.
A side note. The biggest dilemma ldg breeders have is training owners how to "guide and properly reinforce" the pup. A good pup knows what to do. Most owners haven't a clue.
ITA
Justifying an LGD for somebody like me, no sheep or cattle or goats, just rare poultry, with money IS tough. But I think LGDs are underutilized by chicken people. The reason I decided it was worth getting a dog (had only intended to get one) was I got super tired of cleaning up dead chickens that had been murdered for fun. I was tired of my favorites getting snatched. I was starting to be unable to sleep at night for worrying. I spent like $400 on electric fencing for the coops and still didn't feel good about it. So the dog was the next step. I had planned to get one last year, but I got sidetracked, thought it wasn't needed, and then learned my lesson. The financial aspect didn't really play into it for me, but over my dogs' lifespans, I can raise 10 generations of chickens, at a minimum, andI can very likely make back what most people end up paying for an LGD by not losing birds (just this year, I have lost several hundred dollars worth of chickens, enough to have paid for an LGD pup). A friend of mine with 2 LGDs has only lost 1 bird in 5 years to anything like a fox or coon (a snake did get in her brooder house and wiped out all her chicks last year). Before the dogs, she was losing a chicken or more every week.
An LGD of a breed born and bred to guard and bond with stock is probably not the solution for everyone, but it ended up being my solution. Besides, they are kinda fun. They help me with chores, walk around with me until they are bored, then go watch for predators approaching the coop or the driveway. It's fun it watch them...they know what to do already and are trying their best. I just have to stay out of their way and guide them in behavior around the chickens.
I am socializing mine more than perhaps most LGD people -- the ones with thousands of acres and lots of livestock -- do. But my situation is different than thers. We have company over often. We have a neighbor 300-500 feet away (which is about it for neighbors) who comes over sometimes. They have to be well socialized as a result.
Would I get an LGD if I didn't have time to supervise and/or if I had a very small property? No. And research the breeds. Not all might be suitable for your situation.