This achievement technically makes you grind for coins to get the costumes but you can try playing through levels and collect coins along the way. In the original, the costumes were expensive but in this game they are all 700 coins for all the top and bottom wear so technically to complete an outfit you must buy both top and bottom for a total of 1400 coins. In order to get this achievement you must buy every costume you get after you reach Hauntingham. Some costumes you get for entering a new world and others are unlocked by getting all the pages from each world. All you just need to do is Collect all the pages in Sky Castle, Veggie Village, Wrestful Retreat and Gilly Island and unlock Hauntingham. After entering Hauntingham, travel to back to another world with the costume seller and buy all of the costumes in order to get the achievement. You don't need to complete Hauntingham to get this achievement.
Edit: the levels i recommend to grind off of are Burrow Run levels.