This achievement got fixed with the patch 1.05 .So here's everything I did :
1) Finished the tour with a female and get her to level 30 (Got her to Rank 1)
2) Finished the tour with a male and get him to level 30 (Got him to Rank 1)
3) Bought everything on both stores
4) No pop.
5) Here's a video of the whole store, showing everything Ive bought.
Once you done the tour with both characters, the best way to make money is to go online and make a lobby (Private match). Once the match starts you win one point and the dummy quits. You'll get 1000 coins everytime. It takes 1min15 secs per match. Definitely faster than any of the slams.
Or if you only have one Xbox One, you can play a custom tournament, plug your second controller to beat him every matches and get 500 coins per matches. You just gotta put in the settings 1 set of 3 games.
You can also go on the Main Menu - User Profile - Awards (On top right) and them claim all your coins. Do that once you level 30 thought otherwise I don't think it's truly worth it since you won't have much done.