Sarah the fact you work at a vets and get half price cost really is great, owning a kitty is not that expensive initially, the food being the least IMO, but keeping them vaccinated, de-wormed and de-flead is the most expensive and if anything goes wrong, an accident or dental work, or surgery that as you know is where the big cost comes in, in your case it will be minimal, so i would go ahead and work out a budget first and then make your decision, great to see that you are working it all out ahead of time before making an adoption.

An adult cat is a great option, as they don't get adopted so readily and also will not be as lonely as would a kitten, honestly i don't think you will ever regret your decision.

My cats cost me around 70 dollars a year for vaccinations and check up, that is NZ dollars remember, 15.95 a month in flea treatments, about 6 dollars every three months for worm pills, food around five to eight dollars a week sometimes Ten depending on what i buy them and kitty litter around six dollars a month or so. These are just averages and vary from time to time.

Good luck , hope you choose a kitty soon.