LOL, I think we have all had one of these at some point, I replied and said fine you can use whoever you like as long as you pay, as there are a lot of domain appraisal scams about.
This is what they are looking for. last week or something like this I have received an e-mail like that .. 1st I was excited because he agreed with my prices but after that day after day he told me to buy an appraisal from a site that he suggested me and I have not bought one .. I told him several times that i will not buy an appraisal but he allways insist to buy .. if not noone will make business with me.. hah .. such a scammers.