It’s generally more expensive to depart on a Friday, if you have to leave on this day you can still search on Cheapflights to find great options that meet your needs.
Due to multiple factors, expect to potentially pay more when booking in February. For low rates, June can be a great choice for travel to Appleton. Flights to Appleton from Eugene in June are about $350 on average during June, but can be found for as low as $197.
When flying from Eugene to Appleton, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.