Online registration for hotels and guest houses is very limited. And sometimes making reservations on the phone at the most known hotels doesn’t mean you have a place for sure, as they give priority to tours who arrive just before you and take up all the rooms.
I will add up to this page different guethouses as I find trustworthy people that you can communicate in English by email. For a start, here is a newly established family guest house in Sukhum, near the central market. There is no address and you got to contact the owner to access the guesthouse\ eg. agree upon a time you will arrive or make a call when you arrive at the station or central market.
The owners name: Pilia Grigori
The owners email: firstname.lastname@example.org
The owners phone numbers: +79409243727 or +7940961631
The price: 500 rubles per person, rooms for up to 6 people and children go free.
I myself have never been there but a recent traveler from Germany who needed a place in the last minute stayed there for one night and was satisfied with the quality, cleanness and spacious atmosphere.