Rate buy down/payoff and $2000 refinance Credit

[Dylan Wickersham]

I'm getting a seller credit at closing for $8000. My Mortgage broker at Ruoff says I should use $4500 for closing costs and 3500 for rate buy down (3900 gets me to 6.25%). This saves me approximately $100 per month (39 month payoff). Ruoff has a credit for $2000 towards a refinance within 4 years (48 months). Does anyone think that Rates will drop sooner than 39 months by 1% or more?