Any way to hide custom terms from other users?

The ability for users to add terms on the fly is a life saver really, but I am having an issue. This is my setup:

Salary
1. Hourly
I. $10
II. $20
III. etc.
2. Yearly
I. $40000
II. $50000
III. etc.

I have it arranged so that a user may select any of the general salary guidelines, however, they may add a more specific amount if they choose so. That's where your module saved my life. However, I would really like if these custom terms would not show up in the dropdown after being created. I double checked and indeed, every user can see these custom terms after being created.

Now this seems to be a large task seeing as the terms still need to be in the vocabulary to show up in the published node, so am I missing a feature (such as a filter for default terms) or just going about this the wrong way? If it's the wrong way, would creating a vocabulary for these custom terms only and setting up proper permissions be the ideal way?

I'm not opposed to digging in and rigging something up myself if given a proper way to approach it, but I feel like I am missing something important.

Thanks