I also have to agree with Highpower - clean cases are just better. BUT there are a number of ways to clean cases without special equipment. I used a lot of methods before I could afford a motorized cleaner.

You can hand clean them with some of these "wonder" cloths or the lead removal costs. This is tedious but if you chuck the case in a Lee case trimmer holder (less than $10.00) you can spin it with your drill and trim at the same time - I still use this method for certain conditions - like pre-cleaning dirty case mouths.

There are also a number of liquid cleaners available that are very economical - including a home brew of cider vinegar that has a number of followers in some of the forums.

Finally - when you get around to buying a machine - you don't want a "tumbler" per se - you want one of the vibratory case cleaners. My Midway version was the cheapest I could find way back when and it's still going strong.