The route of Riyadh to Lahore is not a short one as compared to the route of Karachi. But it goes approximately or a little less than double. As we know that one of the main reasons of not getting a low rate flight is the distance between the two cities from where you are traveling to where. That is why many people face problems. As we know that there are many Pakistanis living in different cities of Saudi Arabia and most of them are those who went for employment and are even working on very low wages. Such people surely face many problems in visiting their loved ones in their home land.
As we have know that the main reason of the high rate in flight is the distance and also the weather situation due to which everyday price rates increases and decreases. So the distance between the two cities is 2802 kilometers.
To this there is a solution, if you select the flight the takes stop in between like some flights that stops at Karachi airport and then goes for Lahore that means you have not to take a direct flight to Lahore from Riyadh. This would result in somewhat low price. The other way is that search for airbuses, as they are small consisting of less seats but will make an easy journey with good facilities and also with lower flight rates.
The last is that you should take an advice from a good travel agent in such cases.