While you can make a DIY solar filter for your camera using old CDs, that method can damage your camera and we don't recommend doing it on your new DSLR. But Instructables user trophygeek has a new guide to make your own solar filters using a step-up ring adaptor and a UV filter.
The UV filter isn't really necessary, but it will help protect your solar film. A basic filter and the ring adaptor should cost you around $US5. You don't want to skimp on the solar film though, so make sure you buy a high-quality one like the 8x8-inch Thousand Oaks solar film. Although you won't need that much, it's best to have some extra in case something goes wrong while making it.
The full guide is linked below and if you follow the steps correctly, you should have a brand new solar filter for your DSLR at a low cost.
Cheap and effective filters (solar) [Instructables]