I have no problem with people who want to start a new breed (like the American Mastiff)...
Would like to point out that the American Mastiff never has been and never will be a breed. It is a mutt, just like all the rest. They have mixed an Anatolian Shepherd (which is a serious LGD) with an English Mastiff to make what I consider to be what looks as gentle and sweet and laid back as Mastiff, but with the ability to turn instant serious protector in a matter of seconds... a very deceiving looking combo. But felt the need to point out, this is NOT a new breed of any sort. It is a mutt just as much as the doodles are.
I dont understand where people get the idea that purebreds cost tens of thousands of dollars, BYB who bought theirs from pet shops are the ones who charge the huge amounts. know many breeders of several breeds who sell their pet pups, from fully tested, trialed and shown stock for under 500 canadian, so like 400 usd? But then I would never look for a breeder in a newspaper either.
I have YET to see a reputable breeder who sells health tested, pet quality, registered pedigreed pups, from champion lines for less than around $800 and even THAT is a bargain. You MAY get an adult retired show/breeding dog from a reputable breeder for a decent price to perhaps even free, but you won't be finding a pup for $400, so don't count on it.
Take it from someone who knows (but isn't proud of it); BYB pups are much cheaper up front. It's the long term health costs that can surprise you later on.