Just making sure I got this right: someone I know said Suppression Field makes Dredge cost 2 mana to use. I don't think this is true because Suppression Field increases the cost of activated abilities and Dredge is a static ability.

502.47a Dredge is a static ability that functions only while the card with dredge is in a player's graveyard. "Dredge N" means "As long as you have at least N cards in your library, if you would draw a card, you may instead put N cards from the top of your library into your graveyard and return this card from your graveyard to your hand."
Am I correct? I need to make sure, because I'm trying to build a sideboard