Thanks for the Egnatia link. €132/hr for a 40Tdi is not entirely bad. Might give them a ring next time I'm in the area. Wonder if they will have any issues with me flying their planes to Bulgaria (their runways are in better condition than their roads, though)
As for the group share thing... you might want to wander over to the Private Aviation section, where this is discussed regularly.
Personally, I do most of my flying in Southern France and Northern Spain, where the cost of hiring is about the same as you quote, except without the headaches. I pay €117 (£79) per hour wet on a 172XP, and €95 (£64) on a PA18. In both cases no landing fees at the local aerodrome, and away landings are about €10 in Spain and €5 in France (except night landings)
When I fly with other pilots, whoever logs the hours pays for the plane. Usually we fly one sector each, although often the pilot not flying is the busiest, handling the radio and doing the nav, etc.
So in summary, another option you could consider is finding a decent place to hire from somewhere in the continent which is reachable by lo-co, pop over and do your hour building during the weekends. Good for the exposure to different airspaces too.
Anyway, just some random thoughts