Usually tickets purchased in Germany for Pakistan are cheaper as compared to Pakistan. This is called point of purchase which give cheap flight tickets. For example: Leipzig to Lahore return ticket is round about Rs. 112,000 but same return ticket from Lahore to Hamburg would be much expensive.
Use Sky-scanner and Kayak with flexible date option to check trends and cheap flight tickets. Always try to plan well before your travel as tickets are cheap 2-3 months before travel date.
If you use emirates or Qatar Airways, then these airlines have contract with Deutsche Bahn (german Railway). Means you can travel free of cost 24 hrs before /after your scheduled flight from the airport. Its good if you get economical flights from these airlines from any main airport (Frankfurt, Hamburg Berlin etc.) and travel to your required city free with DB.
If you use Turkish airline then you can select transit of upto 20 hrs free and just spend USD 60 for Turkish visa to to see Istanbul. Make sure your flight arrive late night or morning and depart in evening from Istanbul.
Emirates from Hamburg to Lahore on Wednesday normally has natural transit of more than 10 hours, and with ticket price you can claim free transit visa and stay at Dubai. You need to negotiate with emirates for this.
Usually Turkish airline connects most of the German airports with Pakistan. Every month they have 1 or 2 days with very low return tickets on routes which are not busy. e.g, Stuttgart – Islamabad you can get return ticket for around Rs 57,000.
Cheapest One-way ticket from Germany to Lahore:
Use Pegasus airline from Germany to Dubai and then use Airblue for dubai to Lahore. But it’s good if you don’t have checked-in luggage at origin. Connection with Oman Airline is also cheap from Berlin to Islamabad.