There are less than 100 Dandie Dinmont Terrier born in the UK every year. The puppies cost in the region of £2000 and their life span is about 15 years.
Dandie Dinmont puppies are slow to mature and are not available to find their new home until they are 12 weeks old. As with any other puppies you must be able to view their mother and hopefully there father?
There are several ways to find a puppy in UK. UK has 3 Breed clubs and each club has a puppy coordinator that can help you find a puppy or you can use the Kennel club puppy finder service.
There are various other websites that give you information about the breed. Why not come along to a breed show, a Dandie walk or Dandie Derby. There you will meet a mixture of breeders and owners?
There are puppies available please check with Puppy coordinator or Kennel Club website.
https://www.petplanet.co.uk/petplanet/breeds/Dandie_Dinmont_Terrier.htm
http://www.ddtc.co.uk/puppy-news.html
http://www.caledoniandandies.com/index.html