This achievement will unlock as you work to earn all gold medals. It should pop around the time you have got all gold in 3 of the 4 event types. Feel free to spend all the money you want because it will still count towards the achievement. Iceland events are usually the last to unlock and give the most money upon completion but there is no need to grind unless you really want to max out all the bikes.
I maxed out 2 bikes and bought an outfit and had $150,000 saved up when I hit level 20.