The weather is probably better at Inverness than most of the places mentioned so far. It is on the east coast so not as wet as the west, but also quite far "in" from the north sea so doesnt get affected by the fog as readily as, for example Aberdeen and Dundee. This is all my opinion, I have no stats to back it up.
If I was you and couldnt get into the UAS or afford to fly powered, I would go gliding somewhere locally, ie Portmoak, which is MUCH cheaper, and teaches extemely good handling skills and Airmanship, Then go somewhere in the summer to do your PPL. Those prices sound crazy to me..
Good Luck!