Amazon has a BD-related "lightning deal" going on now: from 6 p.m. PDT, and for a very limited time, you can buy
Yanni Live! The Concert Event for a reduced price (unconfirmed at the time of writing). The price history for this Blu-ray title (released on March 16) indicates that the lowest it has been is $16.99.
Thanks to forum member "MikeDaWiz."
Update
Sold out.