〜あげく／〜末に

Both indicate a final result reached after a long, drawn-out process of effort, worry or trouble. 〜あげく strongly implies the outcome was bad or a waste of all that effort, while 〜末に is neutral and can introduce a good or simply decisive result, and sounds more formal/written. Both need a process that took time, so they cannot be used for a single instantaneous action.

• 長い間悩んだ末に、留学することに決めた。

  ながいあいだなやんだすえに、りゅうがくすることにきめた。

  After agonizing over it for a long time, I decided to study abroad.

• 彼は two 時間も迷ったあげく、何も買わずに帰った。

  かれはにじかんもまよったあげく、なにもかわずにかえった。

  After dithering for two whole hours, he went home without buying anything.

• 激しい議論の末に、ようやく結論が出た。

  はげしいぎろんのすえに、ようやくけつろんがでた。

  After a heated discussion, a conclusion was finally reached.