@Chris so where exactly we can find this crucial moment when order is created through someting like $order->add() or something like this because I also need to find exact moment when ps_orders row is created. I need to find out why some values are badly rounded when it comes to tax excluded prices. Is it in PaymentModule.php in public function validateOrder class? It looks like this.
Edit: Yes, this is the crucial function 
validateOrder is the one.
Edit History
@Chris so where exactly we can find this crucial moment when order is created through someting like $order->add() or something like this because I also need to find exact moment when ps_orders row is created. I need to find out why some values are badly rounded when it comes to tax excluded prices. Is it in PaymentModule.php in public function validateOrder class? It looks like this.
@Chris so where exactly we can find this crucial moment when order is created through someting like $order->add() or something like this? I need to find out why some values are badly rounded when it comes to tax excluded prices. Is it in PaymentModule.php in public function validateOrder class? It looks like this.
@Chris so where exactly we can find this crucial moment when order is created through someting like $order->add() or something like this? I need to find out why some values are badly rounded when it comes to tax excluded prices.