I'm an undergraduate student that was offered a role researching for a grant. I was able to get authorship status on a paper and will be attending a conference for it later this year. The professor I am working for connected me with another student at a different university in order to share a hotel room. We will both be staying for the entire week and are responsible for booking our own reservations. Unfortunately, the centre the conference is located at is booked, with only a single-bed room available that we would be required to vacate on Wednesday then move back in.
This student was fine with booking the room and asked me if I was okay with it, but after I realized that it is a small, dorm-like room with a small bed and no futon I counter-offered a room at another hotel a half-mile away with two beds that we would not need to move out of midweek. The student pushed back saying that the other room had a better price (of course, as it is intended for one person) and we would have better involvement with the conference (doubtful, as long as we show up on time).
I'm personally uncomfortable sharing a bed for a week with a student I don't know, and I'm otherwise just a really poor sleeper who has an impossible time sharing a bed with my own father when I need to, and wouldn't fare well at the conference by doing this for a week. However, I don't feel comfortable making this a bigger conflict than necessary, and I don't want to upset my professor by costing our grant more money than necessary by booking my own room at twice the cost. On the other hand, I do feel I have the right to request sleeping accommodations that I am comfortable with. How can I handle this conflict without offending anyone?