You mention that your girlfriend hasn't been sailing before. To be honest, that'd be the first thing I'd be looking at. My wife was initially hesitant about the idea of sailing as a life-choice (she had no problems with it as my weekend sport though). It wasn't until after she went sailing herself that she felt the way I did about the whole thing.
On the other hand, I had a cousin who talked about his dream of sailing around the world. Took a sail up the coast in not so great weather and dropped the idea like a hot potato. The fantasy of fair weather, sunshine, and cocktails in the cockpit came across too much reality for him.
If you don't get past that hurdle, the other stuff isn't going to help. Get your partner onside and the other stuff (while not a snap) becomes easier. At least, I personally have found a dream shared with my wife is a dream on it's way to fulfilment.
Other than that, heed PBzeer's advice on hidden costs. It is a rare boat that costs only the price to purchase it.