I agree with Qwirky. I was at the first Production/VoiceOver Summit he did with Dick Orkin (alone worth the price of admission). 3 days. Gary Owens, Tom Bodett, June Foray, Avery Schreiber, Tom Sharp, and many others whose names I cannot recall, but whose voices I hear everyday. I think Chuck Blore was there too...an amazing thinker.
Bottom line...go. Even if you can't afford it. The practical information is amazing...and it's all tax deductible!