im about to buy a mastiff puppy and i have seen adds for pups for £350 up to £600, i was wondering what is about average and what will i get for the dearer dog. they are both kc reg

Unfortunately it is possible to breed 2 KC reg dogs of the same breed together and get pups that look nothing like the breed they are.However paying extra does not always mean you get better quality but I would not expect a quality dog for £350.
Forget these ads and do some research.Look for breeders who health test all their breeding stock and who preferably breed for the show ring...then you will know they breed for dogs that are close as possible to the breed standard.
All show breeders produce pet puppies..and so are pleased to get enquiries from pet owners.A good breeder will offer you life long support and you will know that the pup has been raised at no expense spared
Archer

Is it a mastiff or a bullmastiff you are interested in, they are 2 different breeds. The mastiff being much larger

The guest said Bullmastiff but would think £350 would be too little for any well bred dog of any breed.

I met a bullmastif this morning for the first time.  He was absolutely delightful.  His owner was 6'5" tall and said he chose him as he would look stupid with a bassett hound which would have been his first choice!

Good choice.

The guest headed her message as a Bullmastiff but in her post she said she was about to buy a MASTIFF puppy, hence my query

Yes, I think people do call the Bull mastiff a mastiff but I thought as it was headed Bullmastiff that was what was meant, but I may well be wrong :)

I have bullmastiffs, and the normal price range is from £650- £950 ish.
Be very careful when buying your puppy.
If you need any advice please contact me.
k.johnson@kingston.ac.uk Tel 01428 658978.
Karen.

£350 does seem a bit too cheap our sheltie was £450 and they arent exactly a large breed