Band of Misfits + Conspirator gives the +1 card + 1 action, and that's only two cards.
This is probably right actually, assuming you had previously played exactly one action, playing Band o Misfits as Conspirator, should give you +1 card +1 action. I find this one of the most counterintuitive rulings in Dominion, and Donald himself changed position on this over time (see here http://forum.dominionstrategy.com/index.php?topic=11518.0 (http://forum.dominionstrategy.com/index.php?topic=11518.0)).
It´s also explained on the wiki http://wiki.dominionstrategy.com/index.php/Band_of_Misfits (http://wiki.dominionstrategy.com/index.php/Band_of_Misfits) under Other Rules Claridications.