I spend £30 odd pounds a month on litter,
That seems a lot for 4 cats I would have thought 1 bag of the wood pellets coating about £8-£9 in the shops here, although we get for just over £5 a bag which should last at least a month.
Cats Protection advise always provide a litter tray irrespective of your cats age even if they are allowed out, if you keep an eye on what your cat is passing, you can spot many problems, e.g, cystitis is very common in cats and needs urgent Veterinary treatment. It is shown up if the cat uses the tray frequently and or, passes blood, something you would never know if you had no tray.
Last year it was necessary to have Trudie a long term CP cat PTS due to bowel cancer, I would like to think that Trudie's untimely death has not been in vain as a lesson can be learned from it, and that is the reason why everyone MUST always provide a litter tray no matter how old the cat and irrespective of the fact that it may go out. So many times I am told oh! I have no need for a litter tray my cat goes out now. Had Trudie no access to a litter tray the cancer would have continued to get the better of her and she would have suffered, she looked purrfectly well and it looked like there there was no reason to take her to the vets, the only reason we took her was because I noticed she was going into the tray more frequently than usual and there was blood on most pooos and drops in the tray. None of this would have been noticed had we no tray we don't know what our little ones are putting in the hole in the garden, do we?