If the earlier £20 offer failed to whet your appetite for ENO's Caligula, how about this one? £24 with a free dinner thrown in.
Lastminute.com are offering a two course meal at Smollensky's (normally £12) with each stalls or dress circle seat (full price £60) - meaning you can sit in the stalls for an effective price of just £12.
You can listen to some clips of the music here.
(Thanks to reader Richard for spotting the offer).