That's not how it works. You cannot connect to another region's store through your console, only the region to which the account is registered - and only that region's content will function with an account for that region*.
If you're seeing, and paying, Saudi prices, you're connected to the Saudi store. If you were connected to the US store, you'd see, and pay, US prices. That means you've either connected to the store through a Saudi (or other sub-regional account which may not have its own store, like Egypt) account or you've bought it through your web browser and it's taken payment appropriate to your IP address... which if you're in Saudi Arabia would be Saudi prices.
Either way, the solution is to cancel your order, buy $70 of PSN cards valid for the USA, and buy the game through your console's PS Store while logged into your US account using the US PSN cards.
*This is to prevent people from connecting to stores with much cheaper prices, and from being locked out of content they've bought due to region conflicts; you can of course set up accounts in any region.
