Amazon takes at least 70% off a selection of Star Trek costumes. Plus, Prime members bag free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $5.48.) A few best bets:

• Rubie's Costume Women's Star Trek Into Darkness Uhura Dress from $5.43 (pictured, $51 off)
• Rubie's Costume Men's Star Trek Into Darkness Spock Shirt With Emblem from $6.67 ($46 off)