Woot offers Mer-Maid Drain Magic Replace Broken or Missing Bathroom Drain Stoppers for $10.99 (reg. $11.99) free shipping with Prime. 

Product Description:
We know you are facing annoying drain clogging issues, or just need a nice replacement for the old and broken sink stopper. Designed with 2-in-1 features and made of all-metal reliable construction, you can easily save your sink drain away from clogging issues, and also give a perfect new look to your sink.

• Our sink drain stopper fits 99% US standard sink drain 1 1/8 inch to 1 1/2 inch. Please be sure to measure the sink drain hole before purchase. It is recommended to be used on drain hole diameter between 1.1"-1.5" COLOR MAY VARY
• Sink stopper or strainer? You need it all. Unlike other regular drain plugs, this innovative design cleverly combines 2 features water-seal and anti-clogging in 1. What a high-cost performance!
• Pop-up cap and anti-clogging frame made of integral molding brass with shiny chrome finish, bullet core made of premium brass, equipped with 3 silicon seal-rings in 3 different positions. It's anti-rust, reliable, and durable. You can trust it.
• No need for hundreds on costly plumber bills, no need for troublesome tools on unclogging pipes, no need for worry about drain cleaners' pollution to the environment.