Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Pasco to State of Oaxaca as you normally would.
Pasco Tri Cities (PSC), located 1.9 mi from the city center, is the airport you fly out of when you book flights from Pasco to Oaxaca.
When booking a flight from Pasco to State of Oaxaca, you may want to consider flying on Aeromexico, Delta or United Airlines as they are the most popular for this route.