Worth selecting a costume with 〜がいある

Grammar Explanation: Worth it with 〜甲斐がある

As a member of the student council, Hitsuji comes up with the idea of having a cosplay theme to help build up excitement among students for the school’s sports day. However, Fujiwara, the student council president, fails to dress up.

Upon hearing him say he doesn’t has a costume prepared, one of the drama club students suggests he pick from their club’s costumes. While Fujiwara isn’t enthusiastic at the prospect of dressing up, Hitsuji is excited by the club’s wide selection.

ヒツジ:: 「これだけあると選(えら)びがいあるね！！一番(いちばん)似合(にあ)うの見(み)つけろね！」; “When there are this many, it's worth it to choose from! Let's find the one that suits you best!”

Key Points

選(えら)びがいある = “there are enough options to make choosing rewarding”
- Here, 選(えら)びがいある means the large selection makes choosing fun / worthwhile
- The idea is not that choosing is difficult in a bad way, but that there are so many costumes that picking one feels satisfying
Casual omission: がいある = がいがある
- This line drops the particle が in がいがある, giving the more casual spoken form がいある
- The full form would be 選(えら)びがいがある
- This が is often omitted in natural speech
これだけあると sets up the reason
- これだけあると means “when there are this many / when you have this much”
- It explains why choosing feels rewarding here: the sheer number of choices makes the activity exciting