Be careful using prepayment via wire. If you do not pick up your tickets at least 24 hours in advance per their policy (even due to circumstances beyond your control) you will probably forfeit your tickets and have to pay again. I am speaking from first hand experience here.

Also, check your tickets for errors before leaving the window. They'll charge you to fix their own mistakes.

PeruRail has a monopoly going - please be careful with them. You cannot win a fight with them unless you don't go to MP.