You may also want to track your current spending on one sheet with columns for different categories. Some individuals will list the budgeted amount in one column and then list the actual amount spent in the column next to it.
You'll need to include more than a basic level of development and calculation in your spreadsheet. There are lots of free spreadsheets on the web. Most of which are very simple and easy to build. People aren't going to buy a spreadsheet that they can get for free. Take yours to the next level by adding all the value you can imagine. Then research on how you can offer a little bit more on the development and functionality side.
At present, some of the most requested types of spreadsheet packages in the market are: 'Spreadsheets for Small Businesses' and a subset of that: 'Spreadsheets for Actors'.
When VisiCalc hit the scene back in the eighties (in the last century), the relatively small group of Apple II users went crazy. It was like manna from heaven for the poor accountants, scientists and engineers who were used to filling in enormous analysis sheets with a pencil. Now, they could use VisiCalc to do the same task, AND calculate the result automatically.
what is spreadsheet in excel
excel budget templates