If the idea of cardboard boxes cluttering up your home office makes you shudder, never fear - there are still inexpensive ways to keep track of that paperwork without having to purchase a file cabinet. Your local mass-market, big box store (ie, Walmart) may have just what you are looking for in their container aisle. Plastic containers, such as those meant to store household items, can also be used quite easily to contain paperwork, and they look a little nicer than cardboard. Be sure to take a sample folder with you to the store so that you can make sure that your papers will fit in the plastic container that you choose, and try to think about whether you'd rather have large containers of paper to lug around or smaller containers with individual projects or years of paperwork.
As long as you can easily look through the box, it can be a good organization tool. Don't purchase something where you can't find a type or section of paperwork at a glance - for example, don't pick a box where you have to lay everything down flat.
These plastic boxes should cost just about $5 each, making them still an inexpensive way to keep your papers in order.