Peru is all about thin mountain air, stone ruins half-swallowed by cloud forest, and plate of ceviche waiting for you when you drop back down to sea level. You want to aim for the dry season between May and September if you plan on hiking the high trails without getting washed out by mountain rains.
Booking flights and guides several months ahead locks in better availability and keeps the whole operation from spiraling out of control financially. We just need a clear plan to handle the $2600 price tag without draining your checking account all at once.
That 0% period is a strict deadline, not free money. If you still have a balance left when the 18 months run out, interest kicks in on whatever is left.