A young adventurer comes to Greece to prevent the sale of his grand parents holiday house, but meets his sandbox love as a badass broker who needs every cent during the financial crisis.

I like this a lot, there is plenty of conflict and tension to draw from this. I can see a clear goal: Save the House.

If I were to nitpick, you may want to try and add an element of a ticking clock, maybe the auction will be in a week etc.

Overall I think it is very good