I know of a Leicestershire breeder, Loughborough to get precise, who breeds cats in cages in small areas....
whilst thus is very sad and cruel I would never encourage anyone buying a kitten from them as it encourages them to breed more and more. Rehoming ex breeding cats from them would be ok providing they are not asking for lots of money... Retired breeders usually go for the price of the neutering. But, be prepared for some behavior issues from cats bred in cages.
I wanted to say that just in case this was the breeder you had spoken with. They have a nude looking website but the kittens and cats are in quite small cages stacked on top of eachother!
I would want to know how the cat has been kept, preferring inside all the time to outside in pens (exception of stud boys as they are mostly in outside pens). I would want to know exactly how many litters she had had over his long. If she is 3 years old I would expect no more than 4 litters really. I would want to know when she was spayed and what screening has been done on her. Also vaccinations, what she has had and when is she due again.
Visit them without expecting to take her home so you can see how she us kept. Then go home and think about it.