Is it ethical to apply to be a conference volunteer (with a registration fee waiver) if I have a fellowship? I am a US graduate student, and recently I have had the great honor of being awarded a large fellowship that provides a sizable monthly stipend for tuition, living expenses, and conference travel.

I plan to travel to a couple of conferences in Europe this summer where I have accepted/pending submissions. However, there also happens to be a pair of nearby conferences a few days prior. These conferences are not as essential to my interests as my planned travel, but still extremely relevant, and if given the opportunity I would like to attend them despite the fact that I will not be presenting a paper.

But conferences are expensive. It is a huge stretch to afford all of these conferences, even with my stipend (which will begin in June, so I won't have had the time to save up). I would like to apply for the student volunteer positions at these conferences, which would reduce registration fees partially or completely if I were selected.

However, I feel anxious that I may be taking away the opportunity from a student who really cannot afford to go. Especially since, as I mentioned, I can stretch myself super thin to make it without the volunteer waiver(s).

On the other hand, though, I suppose it could be argued that I "earned" this financial freedom by earning the fellowship.

Is it ethical to volunteer at a conference where the registration fee would be waived, if I have a fellowship and wish to attend the conference despite the lack of any obligation to do so?
Volunteering is often a lot of work, so it is generally quite reasonable to see the coverage of costs to be not a scholarship, but as compensation for the many hours of labor that you will be putting in as a volunteer.  It is for this reason that many conferences waive the registration fee for their organizers as well.  As such, I think there is no ethical concern about getting a waived registration in return for volunteering.  I would, however, find it ethically problematic to apply for a scholarship (which some conferences offer) when you could be covered by your fellowship.