I have a hotelroom in short walking distance to the convention center, as of yet booked as a single room, but I'm pretty sure that it could be changed.
I now pay £140 for the single occupancy.
IIRC, it's plus £20 if it's occupied by two persons.
I stay from August 7 to 14.
If anyone (that I know personally) is looking for a room to share I'm willing to do so.
You may have to share a bed with me though, because it's very probably only one bed.