Anything wrong with this statement:
if ($shippinginfo["Country"] == "USA")
{ $ShippingandTax["ShippingPrice"] = ($shippinginfo["Quantity"] >= 3) ? 0 : ($shippinginfo["Quantity"] 2); }
else
{ ShippingandTax["ShippingPrice"] = ($shippinginfo["Quantity"] >= 3) ? 0 : ($shippinginfo["Quantity"] 2); }