*That amount and time totally depend on your departure timing from islamabad. and shangrilla is around 730Km from islamabad but on this type of track the distance normally becomes 3 times. so the best option you have is to stay at Chilass (if you leave early) other wise stay at Besham at your first day. and on 2nd day you can easily reach shangrilla. we have returned back from skurdu in a single go on our return in almost 26 to 27 hours of driving (which is not advisible). *
*and about money that depends on 3 factors i.e type of your vehicle (fueling cost)+ your eating Habits (as we always recomend light food at day time on this track)+ your stay place .
*i hope it will help.