Is it cheaper to buy two one-way tickets?

Sometimes. It allows you to fly into one city and out of another (open-jaw), which saves you the time and money of backtracking to your original arrival city.

Should I use a VPN to find cheaper flights?

The 'VPN trick' is largely a myth. Airline pricing algorithms rely more on search volume, cookie tracking, and demand than your physical location.

Finding Cheap Flights from the USA to Europe

To get the best price, book your flight 3 to 6 months in advance and use the 'Explore' feature on flight aggregators to compare multiple departure and arrival hubs. Avoid direct flights between major capitals during summer; instead, look for budget airline connections out of secondary hubs like Dublin, Lisbon, or Oslo.

Use aggregate search engines. Start with Google Flights or Skyscanner. Enter your home airport and select 'Europe' as the destination to see a map of prices. This helps you identify which city is the cheapest entry point for your specific dates.
Set price alerts. Once you have narrowed down your dates, set a price alert on Google Flights. You will receive an email whenever the price drops. Do not book until you see the price dip below the historic average for your route.
Consider the 'Split-Ticket' strategy. Book a cheap long-haul flight from your home city to a major European hub (like London, Paris, or Frankfurt). Then, book a separate ticket on a low-cost carrier like Ryanair or EasyJet to your final destination. Always leave at least 5 hours of buffer time for these connections.
Avoid weekend departures. Flights departing on Tuesday or Wednesday are consistently 15-20% cheaper than those departing on Friday or Sunday. Shift your dates by 48 hours to save significant cash.

Is it cheaper to buy two one-way tickets?: Sometimes. It allows you to fly into one city and out of another (open-jaw), which saves you the time and money of backtracking to your original arrival city.
Should I use a VPN to find cheaper flights?: The 'VPN trick' is largely a myth. Airline pricing algorithms rely more on search volume, cookie tracking, and demand than your physical location.