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.
The common feature among the spreadsheets templates is that they save time and effort and also they make the work and other calculations easier. Planning out things and fast access to data and other information are made very easy when using spreadsheet templates. But most of these templates are unique according to the purpose. The templates can be saved and used as many times as required.
For pure data analysis, the spreadsheet is, indeed, king. To a point...Despite all of these extremely powerful features, the spreadsheet has limitations, which tend to manifest when you least expect it. Often, Murphy's Law applies and the spreadsheet falls over when you are right in the middle of a major undertaking, like month-end or meeting a tight deadline.
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.
excel inventory templates
examples of spreadsheet packages
blank spreadsheet templates