You can get legit AirPods or AirPods Pro for a cheap price using a retailer such as Walmart.
You would need enough money to purchase the real AirPods and the fake ones. So in total, you would need about ~$170-$200 (depending on the fakes you purchase).
Once both sets of AirPods are in your possession, place the fake AirPods into the real AirPods’ packaging and vice versa.
Go to the physical store and return the box that contains the fakes. The most that customer support will ask is “Why do you want to return them,” in that case just say you didn’t want them anymore, didn’t like spending that much money on yourself, etc.
Now after you leave the store with your refund, you can keep the legit AirPods for yourself or flip them online on eBay or other sites for a profit.