That was the "standard game" when we sold in Portland 3 years ago. We had several offers over list, and accepted one about 40k over. Your realtor should know if 17k over is where the game is going to stop, but I do not believe you have a contractual obligation to accept. Even if there is a written obligation, I think there are 100 ways to weasel out if you want to hold out for more. I don't think any of the real estate "contract rituals" actually happen -- and nothing (like, say, earnest money for nonperformance) actually gets enforced by the agents/escrows, you need to sue to enforce contract rights.
Bay area seems to "list" at about 60% of expected sale price, which creates some really skewed games with the realtors. They defend the practice claiming "The bay area is a bidding market" whatever the heck that means. Like many bad things, I suspect this trend will spread over to the rest of the country