I was sent this link a couple of days ago. Looks like a good deal, if you like Opera or want to try it without forking out the sort of money they usually want. Self and Mrs UFO have booked for the Rigoletto but we can't do the other due to a previous engagement.
http://app.e2ma.net/app/view:CampaignPublic/id:1773.255371016/rid:
Enjoy.
UFO