I don't know about the UK but in the USA both tailless and hairless are rare sought after morphs in the rat fancy trade. I myself love the hairless, they're so ugly they're CUTE!!!
Hairless are insanely common O.o There's tons of them in the pet stores, always. I also know several people with hairless rats.
1.0 Western Slender Glass Lizard; Logos
0.1 Charcoal Cornsnake; Morana
1.0 Golden Gecko; Smoothie
1.1 African Plated Lizard; Cypher and Nara