For the least effort you could book United flights. Transfer some of your UR points to United and fly round trip coach for 65,000 points each.

There are a number of SPG properties in Athens where you could use your points.

I'd look at flying to one of the islands - Santorini or Mykonos. You can get flights for about $100 a piece. You'd need to pay for hotels, but they are very cheap (starting at around $50 a night depending on the amenities).