The 1st chance you have to get this is in level 1-2
You need to collect gems to buy something.
A little way into the level you will see a large guy on a tree branch with tentacles for legs walking back and forth. Hop up beside him and hit select. Then simply buy something. I think the cheapest item is 25 gems in the vinyl group, press RB to see those.
The achievement will unlock when you buy something.