I think it's worth it to have experience with multiple platforms. When you create a project in Altium, be sure you save the binary and ASCII versions of the board. If you want to have a chance of importing to another package in the future you'll likely need the ASCII version, but Altium natively supports the binary.
You are much more likely to find Altium in you job later on, and since you are a student, I assume you will be going on to finding a engineering job. If you learn the basics of Altium, you'll be glad you did when your employer asks about it during an interview, or you're required to use it on the job. You don't want to have to learn the basics on the job with someone looking over your shoulder.
If I assume 3 years at $120/yr, that is a very cheap price to pay for some valuable experience(assuming you practice and use it). That's better value than a lot of the classes you'll take in college/university. Also, if you get it go out and find available projects in Altium so you can see how a "real" design looks in Altium.