The Logic Users Group (LUG) is having their 17th group buy, offering up to a 50% discount on The Sound Guy Inc's SFX Machine RT, which offers a large range of effects - it's like hundreds of plugins in one - and is available in the following formats: OSX Audio Unit + OSX/OS9/OS8 VST, or Windows VST.
Full details and the signup form are located here.
Signups will be accepted until November 30th. The normal price is $99 but the Group Buy price could go as low as $49.50 (with 50+ signups) - they are already half way there!