The amount of Avios needed (currency of Aer Lingus credit card rewards) depends on several factors, like the cost of the ticket, the distance, class of the flight and other. What is more, fees may be added to the cost of the award ticket. So there is no direct answer if 50,000 Avios is enough for your flight or not. You should keep in mind that there may be some restrictions and limitations when redeeming for award flight.
If you want to get a travel credit card to earn miles for a flight, consider general travel rewards credit cards. These cards often come with good rewards and generous sign-up bonuses. For example, the Barclaycard Arrival Plus® World Elite Mastercard® credit card comes with great bonus offer – 70,000 bonus miles after you spend $5,000 on purchases in the first 90 days of account opening. Those 70,000 miles are redeemable for $700 in airfare on any airline, anytime with no blackout dates. You will also earn 2x miles on all purchases.