What is the size of the contract? A 190-point OKW contract passed last month at $78. If you're buying a contract around that size, I think $78 will just make it through, but $77 or less will not. On the other hand, if it's a small contract (50 points or so) then you probably need to pay $87-$88/pt.
I assume you have reviewed the latest ROFR info here on the DIS? If not, here is a link to the thread. Latest listing is near the end of the thread (post #2971, last time I looked).
http://www.disboards.com/showthread.php?t=720134&page=199
Your broker should be able to advise you on the price you need to pay to pass ROFR. In my opinion, it's not that hard to pass ROFR. The people who have trouble are generally those who:
1) are compelled to haggle on the price with the seller which then backfires because the deal won't pass ROFR, or
2) don't want to pay a penny more than they have to so they find the lowest-priced contract that passed in the last 6 months and offer the same price.
If you have a contract with banked points then it's worth paying a bit more as "ROFR insurance". I think $78/pt will probably pass but if you want to improve your chances, offer $79/pt. If it's a 200-pt contract, the extra $200 is a drop in the bucket over the lifetime of your ownership. You could even try offering more per point in exchange for the seller paying half the closing costs. The deal would work out the same cost-wise but it may improve your chances of passing.
Good luck!