Maybe, the blockchain has the price of XLM for about 50dollar before, if in that case, this post is not updated yet, then maybe they've just changed the price again to maintain their pool stability to meet their target. But anyways, I am still not convinced to provide my identity for that amount.
So there is few difference rewards? I got information that they will only give 25 USD worth of token, not $30 $40 $50
Or they set this up based on each country, who knows...