You need to earn 3.2 million dollars online AFTER you complete the campaign. I say after because the money you earn online ONLY transfers to your campaign bank after you beat the campaign (win div 1 championship).
After you beat campaign find a boosting buddy and have him create a ranked match and you search through the custom search option and choose to join his game. Once you are in game you will want to kick off and move your guys out of the way by tapping B button and have your buddy return the kick but not run in the endzone and just taunt by running back and forth in front of the end zone while you tap B button and holding down on the left stick to keep them away from him while he farms money by taunting (if you have unleashed then you need to hold left trigger to get rid of it before you can taunt). After he taunts for awhile and scores a touchdown, then just repeat the process for yourself now. This will take a couple hours.
Once you have the 3.2 million required to purchase everything, go into campaign>trainer>equipment. The items you need to purchase are the 5 items that unlock after you beat campaign. The items you want are all highlighted in YELLOW and vary in price from $500,000 to $800,000 (not sure on the prices). Their is one item under each part of equipment (gloves, shoes, helmet, shoulder pads, and sleeves) you need to purchase to unlock this achievement. You do not need to purchase every piece of equipment ONLY the ones highlighted in yellow and they will be the most expensive item.