Yeah, three people seems to be standard. They usually charge by the hour instead of by the person, so it's in your interests to have more movers anyway.
I moved my 1 bedroom place with Haul Zing last year -- they were extremely reasonably priced; easy customer service; and the movers did a good job disassembling and reassembling my Ikea bed, even! They aren't luxury movers -- they want to get in and out as quick as they can -- but they are a great deal.
http://www.haulzing.com/