Well, being a solo traveller it does work out cheaper for me.
Leaving out the lift pass which one has to buy whatever, Balkan Holidays are quoting a package (flight, transfer and HB in Samokov Hotel) for 25/1/14 of £450 (with the single supplement). They are quoting £801 for two people sharing a room.
This year I paid £170 for single occupancy of a room at the Samokov (HB), £60 for my transfer, and £30 for my flights (booking fee). Total £260