3 to 4 days are very less especially when you are visiting from Karachi as at least 3 days will be consumed by Khi to Rwp and Rwp to Khi travel. Anyway I have made a plan for you, tried to squeeze the time as much:
1st Day & 2nd Day:
1st Day, 3 PM Karachi to Lahore via Pak Business Express Train (Smart Class), Reach Lahore 10 AM on 2nd day: Rs.3500/individual
2nd day, Lahore to Abbottabad via Daewoo (Take bus of 1:30 PM and reach ABT at 7:30 PM): Rs. 1400/individual
2nd day evening Abbottabad to Balakot (By Suzuki Bolan Taxi) : 1500 collective
2nd night Balakot Hotel Stay : Around 1000-2000 per night (1 room) collective depending on season peak.
3rd day, 4th Day & 5th & 6th Day:
Jeep from Balakot to Naran/Saiuf ul Maluk/Lalazar/Shoogran/Siri Paye & back to Balakot : About 15000 collective for 3 days, 2 nights
* Third Day, Start very early from Balakot to Naran & then Saif ul Maluk, Night stay at Naran hotel (Accommodation in Tent village around 1000 per tent or in a hotel around 3000 or more depending on rush)
* Fourth day, Naran to Lalazar, spend a few hours there.. Then Lalazar to Naran & back journey to Shoogran, night stay at Shoogran hotel (Around 3000 or more per night)
* Fifth day, Shoogran to Siri/Paye, spend a few hours and then back to Balakot by 2 PM
5th Day Noon/Evening, Balakot to Abbottabad (By Suzuki Bolan Taxi) : 1500 collective
5th Day Abbottabad to Karachi (via Daewoo at 5:30 PM, last bus for the day) : 4350 individual
6th Day : 8 PM Karachi
Its always a better option to book a jeep from Balakot for 2-3 days because if you hire a jeep from Naran to Saif ul Maluk or Naran to Lalazar or Shoogran to Siri / Paye, the drivers will keep pushing you to be back in time so that they can go for another round. You won't enjoy much with such haste. Also it will be a bit costly too to hire jeeps in parts.
In return you can also break down journey from ABT to LHR via daewoo and then Pak Business Express but it is not advisable while returning as you might get late because of road closure etc which might result in missing the train.
Don't choose any other train except Pak Business Express because other train get hell lot of late. If you want to avoid train journey then you can also take a direct daewoo bus from Karachi to Abbottabad but its so much tiring.
Food is usually very expensive there so cook your own food or take ready to eat meals to save a lot on meals. We normally take Mazedar Haleem tin food and it tastes delicious
If you have more questions, feel free to ask