In some cases, a lightning strike can also result in something kind of beautiful. The photo above was sent to Gear Diary by Texas resident Winston Kemp, who was struck by lightning after he went outside to save his pumpkins during a storm.
Food per month per cat is probably going to run you $20. Do not feed junk food or the lowest cost stuff, it causes more problems and more vet trips. Litter per month--price out what you like, most cats go through a 25lb bag of litter every 6 weeks.
I'd guess $500 to $1000/year, depending on how expensive your food and vet is. The important part is that at some point there will be a $500 to $3000 vet bill that you weren't expecting. Last week my cat collapsed and it cost $1800 to diagnose and treat the problem, high blood pressure.