I'd do it!
Of your flex players i'd start Decker pretty much every week, maybe Amendola when he's back and healthy.
So i think you're mostly giving up bench players for the best TE, plus your current TE sucks.
Only having Casey this week is crazy!! He could definitely be desperate enough to go for it!
2013 roster (10-man PPR league)
QBs: R. Wilson, Romo
RBs: D. Martin, Sproles, L. Miller, G. Bernard
WRs: R. White, Amendola, Josh Gordon, Edelman, James Jones, Keenan Allen