
Hi,
If the £150 isn't a typo, then the pups are very unlikely to be registered, or come from registered, health-tested parents. Even 10 years ago puppy farmers were selling dalmatian pups for £300. I would expect well-reared, registered pups to be in the £350-£450 price range, with maybe £500 from top stock.
Most definitely the puppies should be BAER tested, and have a certificate proving that they can hear in both (ideally) or only one (okay for a pet pup but not for potential breeding stock) ear. Both parents should also have been tested (you should be able to see the mother's certificate, and a photocopy of the sire's) and have normal bilateral hearing. No responsible breeder will sell a totally deaf puppy, so that possibility can be ignored.
If a puppy is badly mismarked - patched, say, or with one (or two, but that is unlikely because it is probably totally deaf) blue eye, or has very few spots, or far too many, or they're very badly distributed, or it is spotted in a colour other than black or liver, then a lower price is often charged - around £250.
If you go to
the Dalmatian Telegraph you will find lots of info about dalmatians, and a list of litters available from reputable breeders. Good luck.