Depends on condition. Remember that hundreds of thousands of M&Ps were made, so they are not at all uncommon. I'd say you should find a shootable but kind of beat-up looking Victory for $175-200; a parts gun would be less. An unfired (or barely fired) Victory with good external appearance would bring three times as much -- maybe $600-700? In between condition would bring in-between prices, but the distribution is not regular. An average Victory -- used but not abused -- is probably a $300 gun.
Military holsters are collectible in themselves. I don't know much about them, but a vintage Rock Island military holster could go for $100 or more, depending on the model for which it was designed.