So, I've got an EDH deck featuring Wort, Boggart Auntie as my General. I really want to exploit her ability for all it's worth, so I've been looking for different goblins that have "Enters the Battlefield" effects and/or sacrifice effects. I can across two with Echo that seem like they'd work really well: Mogg War Marshal and Stingscourger.
Let's say that I cast Mogg War Marshal last turn and that I have Wort in play. During my upkeep, can I decline Mogg War Marshal's Echo cost, sending it to the graveyard and then retrieve it with Wort?