First, Kathy, an XLS file is an Excel spreadsheet file. You’ll need a spreadsheet program, like Microsoft Excel, to open an XLS file. The good news is that you can do this online for free at Google Docs and Spreadsheets. All you need to do is sign up for a free Google account (if you have a Gmail account, you already have one). Just go to http://docs.google.com and you’ll be able to open the calculator.

Terri - as far as the cost, I haven’t decided yet, except that the very most for any of the products will be $17. With the Rollercoaster pricing, there will be a range - most likely from $10 - $17. So, when you get to the page, the price could be anything in between that range. If you don’t like the price, refresh the page and you’ll get another price - could be higher or lower. You can keep refreshing the page until you find a price you like.