wow, that's steep..
you can copyright your music online directly with the U.S. Copyright office for $35. you just fill out the forms, upload your music, and pay uncle sam via plastic money (credit card). i did it with my last band, a little bit of navigating but pretty painless.
http://www.copyright.gov/eco/
Advantages include:
Lower filing fee of $35 for a basic claim (for online filings only)
Fastest processing time
Online status tracking
Secure payment by credit or debit card, electronic check, or Copyright Office deposit account
The ability to upload certain categories of deposits directly into eCO as electronic files
Available 24 hours a day, except for routine maintenance every Sunday from 12:00 midnight to 6:00 AM Eastern Time
Average Processing Time for e-Filing: 3 months
Average Processing Time for Form CO and Paper Forms: 10 months
Acceptable file types:
Audio
.aif, .aiff (Audio Interchange File Format)
.au (Audio File)
.mid, .midi, .rmi (Musical Instrument Digital Interface)
.mp3 (MP3 Audio File or Layer 3 Audio Compression)
.ra, .ram (Real Audio File)***
.rmi (Resource Interchangable File Format)
.wav (Windows Wave Sound File)
.wma (Windows Media Audio File)
Text .doc (Microsoft Word Document)*
.docx (Microsoft Word Open XML Document)*
.htm, .html (HyperText Markup Language)
.pdf (Portable Document Format)
.rtf (Rich Text Document)
.txt (Text File)
.wpd (WordPerfect Document)
.wps (Microsoft Works Word Processor Document)**