The cost discussion cycles through a couple of the email lists pretty regularly. Generally the people in the UK and me are on one side, and then mostly the US breeders/a few pet owners are on the other, saying they hate this particular discussion etc etc.
I've heard allthe arguments from US breeders, and still, like most of the UK breeders/pet owners, I do not really understand why they charge so much for puppies. I've heard the small litters, the cost of stud fees, the costs of health certs, the testing, the vet care. Yet vet care is generally cheaper in the US than the UK/Ireland, the litters are the same size, the stud fees around the same according to UK breeders, the testing the same. There's a UK breeder who runs one of the lists who notes that she breeds malinois, one of the rarest dog breeds in the UK and US where there are also small litters. She noted some were complaining on a malinois list why malinois puppies in the US were so expensive at $650!! She thought that was pretty funny -- expensive is relative depending on where you are and what breed you are talking about.
I do know far fewer UK/Irish breeders test than in the US. On the other hand many have long-lived healthy lines and once you research and know that, having certificates did not seem to make that much difference.
Overall (and I am totally generalising here of course) I think it is that cavaliers have been given a kind of image in the US that they don't have here at all -- of being costly dogs for the wealthy. NO ONE views them that way here -- they are as commonly seen as labradors and GSDs; I see far more cavaliers than cockers for example. There are seven in my close neighbourhood that I see regularly on walks, and I live in a working class area of Dublin, not a posh suburb. They are often the dog of choice for little old ladies... But they are far rarer in the US. So market demand and their cachet makes it possible to charge $2,500 for a pet quality puppy that over here would cost â‚¬450 ($600). Be aware that when brokers charge â‚¬1800 for Irish puppy mill dogs over the internet, you are paying all that money for a puppy that the broker paid about â‚¬50-200 for. All the rest is pure profit.
Oevrall I think it is far better to deal with a reputable breeder in the area that you live. Reseraching good breeders from abroad is difficult, and once you add on all the transport costs the prices begin to level out, plus with a good breeder from your own country, you have them as a resource as your puppy grows.
All that said, I could not have afforded a cavalier if I lived in the US, I don't think; much less two. It's an awful lot of money to pay up front for a puppy and that would have been hard to manage; I'd have likely gone for a rescue mixed breed smallie. Though now I think I will always have at least two cavaliers!!
Edited to add: Don't get me wrong, I do think that ideally testing should be done. But when it is not done widely, you use other approaches. And I think now I'd be more concerned about SM, which you can't test for, than MVD anyway.