The USCO has proposed significant increases in copyright registration (and other) fees. You can read the whole shebang here, but the gist is that it is going to cost you more to file your registrations, no matter what your art is.
For example, a group published photographs registration is now $55 but it’s suggested new cost would be $100. That’s almost double and, although the USCO does make a good argument for increasing its fees, it’s going to hurt a lot of artists.
The good news is these new numbers are not yet written in the proverbial stone. Instead, they are seeking public comment before deciding on final numbers to submit to Congress.
You have through July 23, 2018 to submit a formal comment (see link above) and I encourage you to do so. However, please remember that it will serve no purpose to get nasty in your comments. Politeness (and logic) can go a long way. These are public comments, so think before you write.
Whatever the comments the USCO receives, it’s safe to say the prices will go up–it’s just a question of how much. For now, though, they are as they have been. I suggest, if you’ve been putting off registering, now may be a good time to catch up.