You have a few options. First you can order your own appraisal and keep it to yourself, you have no obligation to disclose that you are doing so. Since it is vacant land, the appraiser will not need access to it like he might if it were a home that needed an appraisal. Tell him you are in a rush and he will get it to you before the seller's appraisal. Second, you can look through newspaper notices, classifieds or county records for recent vacant land sales. Third, you can wait for the seller's appraisal. Chances are no matter what you offer, if it is low in his mind, he will likely wait for his appraisal anyway, either to show it to you or to get his own idea of what its worth. Telling hiim you are a broker is no big deal because he will know you are also the adjacent landowner anyway and that you are not looking to "flip" the property. He does not need to sign a broker's agreement with you, if thats what you mean. Finally, it is always safest to close with a lawyer. The money you "save" will not be enough to make up for the expense if there are problems. Also make sure to order title insurance as well.