I have a lot of experience with AirBnB, so I'll try to offer some insight. In my market (college town, population 250k, not much draw besides the university/college football games) we manage to stay pretty booked up on AirBnB. Our occupancy rate can range anywhere from 60-85%. That's definitely a big swing, but we just acquired a new AirBnB property that we began renting this month, so we're still working on adjusting rates properly. Anyway, one rental is a single room in our house, that rents for about $40/night or $75/night on weekends. It's a nice space with private outside access, private bathroom, and fridge/microwave. We have had many people stay here for weeks or months at a time. The other rental is an entire home, a 2/1 that rents for $65/night or $90/night on weekends.
Most people traveling on AirBnB are thrifty, so I don't know that $100/night would work with so much competition around. If you did separate rentals at $50/room, that might work and appeal to mid market people. This still gives you the $100/night that you want, but is much more reasonable to thrifty travelers. Most people there are probably there for at least a week so $100/night is a bit much. If each bedroom would have access to their own bathroom, this would probably work really well. If it is a shared bath, your rate may need to be a little lower. You can put a statement on your listing that the full place is available as well, and groups may send an inquiry for booking.
I am extremely frugal but would still definitely be willing to pay $50/night for a nice, comfortable place over a hostel. You'll probably see a lot of people in their 30s-40s who do not want to stay in a hostel, but are also unwilling to pay high resort rates.
I think this could work for you, especially if in an area frequented by travelers/tourists. Also, one trick to add a little cash cushion in case of low bookings - add a cleaning fee of $10-$20 (this is total, not per night). This works well because if someone is staying more than a couple nights, that's not much additional money on a per night calculation. Also the cleaning fee can detract short term (1 day) bookings, meaning you get longer reservations, and spend less time with turnover (laundry/trash/dishes, etc). AirBnB doesn't include the cleaning fee when initially viewing rates so it will just show $50/night and people will think it's a great deal, then after they get started with the booking, they will see the cleaning fee. I know I have found places before and got my heart set on them before seeing the cleaning fee, so usually I just accept it. $10-$20 total isn't much to add to a booking.