A little over $200 are going to go to tips, whether you pre-pay or you wait until the end. You are not going to have enough capital to do any excursions with the $300 you'll have left over.
My advice is to forget about that and just have a great time, eat like a king, plan on strolling through the cities and learning all you can about different cultures and make lifetime memories.
Not everything costs money. But the kind you're thinking about do and it will be more than you have.