Just in case you're thinking about B2B - here's a link to vacation house rentals by Wrightsville Beach, where the swim start is (and walking distance to T1 and bike racking on Friday):
Lots of nice properties in all price ranges! They have prices on most of the houses if you click for individual information. I've seen everything from $500/week to $2500/week for places that looked nice.
Of course, since the finish line is in downtown Wilmington (9 miles away), you will have to figure out how to get transportation back for you and your bike after the race. If you're doing the full, probably riding your bike back tired in pitch blackness isn't an optimal plan.