Do you wanto call from internet to a mobile/landline in Saudia Arabia?
www.Globe7.com gives you the best price in that case. But dont expect too much price reduction. It would still be around 10/12 PKR per minute.
You can try telenor middle east package where they charge you PKR 4.99 per 30 seconds so around PKR 10 per minute. Thats the cheapest in cellphones.
Or if the other party in Saudia have access to internet, you can download Skype from Skype.com.
Or if they have a wifi enabled cellphone in Saudia, get a virtual number (DID number) for Pakistan and divert the call to your saudia number. from a VOIP website, ask the party in Saudia to log in to the account of that website from their cellphone. Now you can call the virtual number which will be charged as a local call.