In the time-honoured Ozbargain tradition of combining multiple deals, we now have the usual T.M. Lewin shirts for $40 (formal, casual and "evening") combined with the 30% off everything Click Frenzy sale to give a price of $28 per shirt with free delivery.
I believe this is the cheapest they have ever been.
You can also try to get your 4% cashback from Cashrewards, etc, as well, however it appears you need to go through the above link to get the $40 shirts, so likely not possible.
I don't own any TM Lewin shirts as yet so can't comment on them, however they have been discussed here a number of times so do a search if you want to find out. Also happy to give TM Lewin my business given some of the good customer services stories in the $20 jacket/pants thread (which itself seemed to be a price error).
48 hours only, so get moving.
Edit: try this link if above link isn't working for you.