After trying a few seasons in MyGM with a stacked team and still not getting this achievement, I decided to use the Miami Heat with default rosters. Go into MyGM in the menus and scroll over to BUSINESS SAVVY (by using RB) and buy Business Savvy Level 1. This allows you to change ticket prices for each home game.
After doing this, back out to the menu again and scroll over to BUSINESS. Hit RT and you'll be at Gate which is where you set your ticket prices. I slashed prices in half for both Tickets and Parking and after simming the entire season, the achievement popped during the MVP screen.
Good luck, and hopefully this works for you guys since I couldn't find a guide anywhere.