At £80 for a double room for one night, The Manor House Hotel was the cheapest accommodation I could find in Oxford without staying at the infamous Nanford or a hostel. Proprietress was extremely friendly although described the town centre as a ten minute walk away - the walk is actually 25 minutes. Lady was devout Greek Orthodox and had many religious images around the hotel which was interesting but a bit unnerving at times. Room was clean if a little faded/outdated. Shower was very feeble and dribbly. Bed was clean, big and very comfortable. We were assigned a room in the building next-door and given our own front-door key which turned out for the best as we arrived back very late. Breakfast was included but cannot comment as we overslept and missed breakfast.
Would recommend to anyone looking for budget accommodation in Oxford - but don't expect it to be cheap - staying anywhere in Oxford costs a fortune.