[PC] Overwatch Standard / GOTY Edition - MXN 349 (~ $24.38 AUD) / MXN 459 (~ $32.06 AUD) @ Battle.net
Was gonna post this earlier but LlamaFarmer beat me to the sale. Nevertheless, you can find the original post here for the Australian deal.
I think it's worth the extra 5 minutes to set up a Mexican account to save the few extra dollars as the game is giftable so you can transfer it to your main account if you have games purchased under that account. Also this is the global version of Overwatch so you can play in any region.
You need to create a new Blizzard account with Mexico set as the country of residence, then you can purchase it from the link.