Wings are one of Aion's most recognizable features, but Aion 2 also made them part of character progression. NC introduced a Wings Enhance System that can add stats. That does not mean your next pile of materials automatically belongs there.
Compare the next step, not the finished item
Look at the immediate gain shown in the enhancement UI and compare it with your next weapon, armor or accessory improvement. What content would the extra stats help you enter or clear? If you cannot name it, hold the materials until the decision is clearer. The same update that added wing enhancement also raised several stat caps, which makes old “best value” claims particularly time-sensitive.
Do not confuse appearance and performance
A wing skin you love and a stat upgrade are different purchases. Treat cosmetic appeal honestly as cosmetic appeal; it does not need a fake efficiency argument. For progression, record the materials and expected benefit before confirming an enhancement. A few deliberate decisions usually do more for a character than a long list of impulsive clicks.