Barcelona, Spain
Barcelona is the most modern city, Mediterranean climate and a very colorful area.
The best time to go would be the summer or the spring but just be careful because there will be a lot of tourist there.
Flying
I found that tickets range anywhere from $1,084- 1,217 round trip
It really just depends on who you fly with and how many stops you want to take
To get there depending on the stops it can talk you anywhere from 13 to 26 hours.
What will you need?
The stuff you would normally take on a vacation: clothing, camera, etc.
Documentation
You will need a pass port. Those are about 135 dollars that I could fine.
Something might needed
Depending on how long you are there you might need to know how to speech Spanish or you could take someone that knows Spanish. Because I don't know anyone that knows Spanish I would probably do the Rosetta stone set 1-5 and that costs about 275.00.
Who I would travel with
I don't like traveling alone for one thing so I would probably take my best friend. It's a once and a life time trip and she would be the only person I would actually want to share it with.
Food.
For food and other things that we would most likely buy and do we would probably take about 1,800 with us. That includes hotel, food, shopping etc.
Total
Over all for the both of us it would cost about 4,500.