How do I make a developer product like this???

Edit: Hello. I have created a developer product called "Tornado Alley TM 3: Emerald Stone Stuff" I would like it if someone knew how to make it so you buy it, but once you buy it, in the shop it would add it's items or stuff. It would add possibly more land and buildings and status all from emerald. Although once in the shop you can buy the stuff and use it. It will have it's own little icon in the top right corner. Or all items will be previously in, but once you buy it. it just unlocks them. (I like the adds them in one better, but which ever one is easier. Remember I'm only a very early beginner. Thanks for the help!

If you know how to do it or the script(s) please type them as an answer. I know it's not my own work, but it is way too confusing.

-- Example
answer.here:add()