Is the system really that hard to understand? It has nothing to do with one's knowledge of English, it's common sense. Study this:
1 stage costs 12 pounds. You buy as many stages as you want. If you buy 2 stages, you will actually pay for 2 stages, which will give you 2x12 pounds. If you want to upgrade your 2 stages to have all 3 stages, you will only have to pay for the 3rd stage because you already own the first 2! UNPRECEDENTED SIMPLICITY
Conclusion: if you wait for S3, you'll a) wait for an extremely long time and b) won't win anything except for being left out of the fun and laughed at.