They are the ideal tools for companies who lack the financial resources and / or the staff required for generating spreadsheet solutions with specific programs. At present, the most requested types of ready-made spreadsheet solutions are "Spreadsheets for Small Business" and the subcategory "Spreadsheets for Actors".
You can build a reputation as an expert spreadsheet developer. This certainly doesn't hurt the resume. Using Excelville.com to sell spreadsheets allows you to set up a profile with your work, biography, and other info that certainly makes for good conversation material during interviews.
You may want to create a workbook with multiple sheets for various aspects of your budget. You can have one sheet that keeps track of savings and investments and another sheet that lists your monthly bills.
Early databases available for the PC market were simple two-dimensional solutions and were essentially designed as a record-keeping system. However, when computing power increased, the advent of the relational database became an affordable option. Applying the rules proposed by Edgar Codd, the Database Management System (DBMS) became a reality, with products such as dBase being widely implemented in the desktop market.