The prize that you receive is based on the chapter you are in when the prize is redeemed.
You MUST complete the "Advanced Scouts" research in order to be considered in the "next" chapter!
Once you've accepted the prize into your inventory, its value will not change. This is still true even if you have not yet placed it in your city.
The quest series is running on the beta servers from February 7th through February 17th.
It will run on live servers February 14th through February 25th.