Most folks know about iStockphoto for finding quality photographs at a reasonable price. It is a source for finding images that you need for quality or commercial work.
iStockphoto now has audio and video content that you can incorporate into your videos. It is also an option to generate money by creating content for others to buy and you share in the income.
You might need a bit of music that is well made. You are willing to pay for it but don't want to fork up a house payment to do so. You can type in a key word or musical type and a list will appear with the name of the track, beats per minute, the length of the music and how many others have downloaded the track.
You can click on the track name to sample the track and get more information. iStockphoto media is sold in credits. You have to purchase credits first and then when you find what you want the credit is subtracted from your account.
The video feature works the similar fashion. In both cases, you can preview to see if the track or video matches your needs. Both the audio and video tracks are branded to keep folks from bootlegging.
I would also check out the freebie of the day and the dollar bin to see if there are options you might want to recycle for an affordable project resource. The site uses a credit system that has three different payment methods.
Royalty free does not mean free to use without payment. Depending on the stated conditions of use you as the customer purchase content from the site and then are free to continue to use that content according to the terms of service.
Which you should always read. Always.