If you click on each levequest and scroll down a bit it'll show how many leves it takes from level to level assuming you're at 0 base EXP, having just gotten everything from 1-50 recently it takes around 11-14 per level range if you're doing courier (low number if you make things yourself and all are HQ). 50+ would work the same way so you can go with their number to be safe but know you most likely won't need as many as listed due to exp left over from previous levels.