FTB,
You're right on! Just some round numbers:

255 70-76 Seat aircraft (you can throw 6 seats back in the other 100 jets)
12 hours / day block (assumes no spares and all jets fly every day)
365 Days / Year
$100 / Hr more to operate at mainline (yeah I know--it would be no where near this)

255*12*365*100 = $111M / year

Subtract out all the overhead, inflexibility, other costs associated with operating on another certificate. Gained synergies, extra seats,....

All this outsourcing is saving DAL less than 20M/qtr! Get this stuff back to mainline! By the way, the above are extremely conservative numbers!