The whole arc, from the first doubt to an ordinary week

Buying all three at once is not obviously the right call, and it is worth saying so. If you are two weeks from a flight, the decision workbook will sit unopened, and there is nothing clever about paying for a stage you have already passed.

What the bundle buys is the part people underestimate: the problems arrive in sequence, and each one feels like the last one until you are inside it. Plenty of people who were certain about their destination reopened that question in month three, from a flat that never quite worked, without knowing which of the two was actually wrong.

Having the next stage already on your desk changes how you treat the current one. It is a smaller thing than it sounds, and it is most of the reason the set exists.