Health: the routine vet year
Boosters, flea and worm treatment and a yearly check. Illness is on top of this, and nobody can put a number on it for you. See this line on the bill

A routine vet year: what it costs
Battersea and Cats Protection split the routine vet year into different lines, so their totals don't match. Neither includes a day of illness, so I'd treat both as a floor.