To add to and summarize the other responses, your original post is worded so many of us have questions about what phone you mean. The Samsung Galaxy S2 is an older phone that predates the Galaxy S3. There is a Samsung Galaxy Note 2 that just came out and has a 5.5 inch screen as well as a pressure-sensitive stylus, which is good for those who like to draw/sketch and also has some other uses.
Now, since the Galaxy S2 is an older device, there will be a question about how long it will receive updates compared to the S3 or Note 2. I know that many people don't care about having the latest and greatest devices, but if one of those "wow, now THAT is a great feature" situations comes along for a newer version of Android that an older phone never gets updated to, you might find some disappointment.
Then of course, you have the price issue. Here in the USA, very few people buy their phones off contract, so we pay $100-$200, or in the case of the Note 2, $300, keep it on the same cellular carrier for 1.5-2 years, and don't need to pay the full price for the phone. Things ARE different over there, where you can take your phones between carriers, so paying full price lets you take your phone with you, and you have options.