51k miles at <5 CPM is going to cost you $2550. The question then is can you get 24 segments at <$106/segment. I'd bet you can as I think I've read of good segments being $30-40 each. 24*40=$960, a good bit less than $2550.

Even if you got 4CPM, you'd be looking at 2040. You'd have to find a CPM of 1.8 to make the miles approach less than good segment runs (if I have my good segment run $$ correct).

I think most good Premium fares are ~10CPM. Since you'd need 22000 miles of travel on 1.5 EQP fares (33000 / 1.5), you'd be looking at roughly $2200 cost.

I'd go look for segment runs and see what you can find.