Tezgam has 4700 (per person) fare till RWP and 4000 till Lahore. Karachi Express had 4000 till Lahore. In Tezgam, most bookings are not available to "aam admi" as they are reserved for railway officer quotas or army quotas. Kids have half fare.
Night coach (Shalimar) has 12000 fare for 2 person cabin (1 kid extra free)... or 24000 for 4 person cabin (2 kids or 1 adult extra free).
Best chance to get booking is in Night coach (Shalimar) as its private.