I agree that some of the breeds look similiar at a first glance until you look at them objectively and seriously.. I think that most breeds when they first come into the UK have a higher price tag. Sometimes it is based on attracting really serious breeders/new owners and put the cats beyond the BYBs.However come what may they will get their hands on them and they will become another cross breed for money.I am not knocking cross breeding or outcrossing if it has an objective, most of the new breeds have their roots their until they have what they consider the final look of the new cat breed.
Most people working on new breeds lose money hand over fist, as all of the progeny as they work along the pedigree, have to be petted out, usually at a loss, neither, would be, new owners or established breeders are interested in pedigree cats that have yet to have a proven market place and easily recognised name in the cat kingdom,
I agree the use of term rare breed if used in the wrong context can smack of get your cheque book out we're possibly going to fleece you. However in most cases it means if you are looking for a different breed to show off, or are enthusiast about embarking on a new adventure come on board ours.