Thanks Joedy.
Good question, but I don't have a specific number in mind. Given that I'll have to spend about a grand on a helmet and insurance (I've been a closet biker my whole life so have a wardrobe full of jackets ), I suppose I'd like to keep the bike cost to around £6-6.5k ideally,; then again I'd stretch that to anything under £10k for the right bike, or buy used if that made more sense.