Without beating around the bush, there are plenty of discount services out there. Redfin and Zip Realty come to mind.
And without beating around the bush, talk with a good mortgage broker on how to bring the interest rate down. Yes, buydowns are one way. But there are other techniques, too. And, really, I'm not sure what you're asking for will save you as much as you want or need. 0.8% of a $700,000 purchase is $5,600. Every penny counts, of course, And the $5,600 (1 point on a $560,000 mortgage--that's a $700,000 mortgage with 20% down) will drop the interest rate by 1/4%--at today's figures from 5.25% to 5.0%. Still, check with a mortgage broker (and your accountant) to make sure that that's the best strategy for you.