Is there a sale pricing plugin for mp?

Hi MarketPress! Thanks for your awesome plugin! I am interested in a sale plugin or to know if there is a way to add sales per department or per group? like if you buy 3 you get 10% off and if you buy five you get 20% off and so on... And to provide blanket sale pricing for seasonal sales. Also would like to have an option to omit the shipping for in-store pickup. Is there a way to do that?

Matt Durand
Kozo Fine Art Materials