Disclose Contract to Third Party Neighbor - Bad Idea?

[Luke Stone]

I'm debating if I'm crazy for considering this. The owner of the second half of a duplex I recently purchased has asked me if would provide him with a letter stating how much I paid for my unit so he can appeal the property taxes. The recent tax assessment came in $20k higher than what I purchased my unit for in May. So I am considering doing the letter or even just giving him the contract minus some personal info. If he wins his appeal it will help me in mine. His appeal hearing date is way sooner than mine... Also I would like to eventually buy his unit and I got a really good deal on mine (seller was distressed and needed to sell quickly). I think this may set a good base price for negotiations. Are there any major pitfalls to disclosing a contract?

[Greg H.]

@Luke Stone

I was referring to a Sales Survey which is often mailed to the buyer and seller .  Basically, it is the Appraisal District fishing for information 

Your neighbor is going to need a copy of your settlement statement to be successful and I would do it if I were in your position.  Being a half duplex you share walls, roof and fences at a minimum.  You are going to need each other's cooperation with repairs over time and this would be a great goodwill gesture on your part

There is no downside for you as in Texas the tax value is no indication of market value and does not effect the market value. A higher tax value means but one thing......you pay more property taxes