Budgeting is really smart of you. Good luck!
I think as long as that system works for you it's all good. As for expensive things you can think of any extra money rolling over to the next month as a way to save up for something more expensive. I do that, when I know I'll spend more money. Like around Christmas time for example, when I buy gifts for people.
When I budget, I figure out how much to set aside for: bills, rent, food, emergency funds for things breaking for expensive healthcare bills...etc, anything fun, and money to put away to save for house/retirement/IRA/kind of stuff. I also shop around if I can get a better deal for internet, insurance,.etc. or like right now I'm looking at therapy prices.
That way the price of things don't matter as much because I can choose to buy something cheaper one month and wait to buy something expensive.
..like I always buy things on sale for food and make my own food, which is cheaper and save some of that money to help cover a healthcare bill or something. Or rollover one budget's fund into the next month to pay for something a little more expensive. Or I put it in the emergency fund.
It keeps me from overbuying or being lazy about what I buy and being thoughtful so that I don't waste money I really should save and always have at least some fall back cash in emergencies and some ability to save up for things. That was I don't panic.
Because something always breaks, or the car needs fixing, or a healthcare bill.
