B&H Photo has these on sale for a limited time for only $24 for a two pack.
They show as $49.99 but there is an instant coupon to click on which takes off 52% and no shipping charges and no tax to certain places…
https://www.bhphotovideo.com/bnh/controller/home?O=invoice&A=details&Q=&sku=1276272&is=REG