I agree with Debra, you have gone this far and the sellers agent can provide you with the same comps. As to the offer, it is not as much about the price as it is about it being the right home and meeting your time requirements. Remember the seller is under no duress to sell as their home is not ready for them to move. Based on a quick search of the property it is in excellent condition with may extra's it does not seem unrealistically priced although it has been on the market for 123 days. There have only been 9 sales over 500k in Rehoboth in the last 12 months and there are 3 presently under agreement. I'd be happy to give you some direction, but at the same time do not want to jeopardize your open communication with the sellers agent. call me if you'd like.