if you don't have a digital camera, then it's going to be expensive
Don't I know it! I usually take TONS of picture hoping to get at least a few good ones! You can'timagine how many "backside views" or half cats, or pics of cats that look like demons I have collected over the years

And some are just easier to photograph than others (in my case it's often strays or other people's!)

Good luck, and remember that we want to see the results.