My husband and I stayed at St-Denis for one night. We only paid $70 so we were not expecting much but were pleasantly surprised. While the room was basic and on the smaller side, it was enough room for a king size bed and a few desks/chairs, and it was clean with a newly renovated bathroom. The location is great too, right in the heart of the Latin Quarter.
I thought it was a really good value considering we only paid $70/night.