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.
At our house we spend 460/month for 2 adults, vegetarian, make meals from scratch, but buy some luxury groceries like pesto, avocados and cherry tomatoes. And spend another $120/month on dining out and cafe treats. That is still under $300/month per person. I think your costs are in line.