Option to have an "early-bird" special price which is in effect until such a date. Once that date has come, the product reverts to the normal price. So product X is $9.99 until June 1, 2012. After June 1, 2012, product X is $15.99. You really only need two additional options; earlybird price / earlybird date.
Timbre Design commented
Actually that is not correct Patrick, there is no sale price option for bookings.
Billy Sobczyk commented
better would be an escalating earlybird price. Regular price is $150, Buy before May 1, and it's $100. Get in before July 1, and it's $125. After that, regular price. So, I guess it'd be nice to schedule a series of "sales" on a single item.
Patrick Garman commented
This is already an option within WooCommerce - when you enter a price right below it you can schedule a sale price. Just enter your sale price and the scheduled dates.