We reserved (and payed) a room already from Tacna bus station, transfer included, where it was offered by a bus company.
Positive: The young lady who apparently runs the place alone offers also tours (through an agency) and can give you a discount on that.
Negative:
1. No transfer was waiting at Arequipa bus terminal, nobody was answering the phone. Thus we took a taxi. Apparently the lady didn't know that we were coming.
2. The flyer we saw in Tacna promised internet and TV in the rooms. Neither was there.
3. The day we left for Colca Canyon, we were told to get up at 8:00 to have breakfast. We showed up at 8:10, no breakfast. The young lady showed up at 8:25 to prepare it.
4. At night it took rather long until somebody opened the door.
5. No room cleaning during our stay.
We stayed two nights, but after the Colca Canyon tour we moved to a different place. I think you can find better places even closer to the center for the same price.