Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Glasgow to Spokane as you normally would.
Spokane (GEG) is the airport you will fly into if you book a flight from Glasgow to Spokane. You should not have trouble finding flights to Spokane from Glasgow; the airport handles an average of 0 inbound flights from Glasgow per day. You should also have plenty of airline options to choose from since 3 airlines have flights to the Spokane airport from Glasgow. It is only a 5.6 mi journey from Spokane (GEG) to Spokane’s city center.