If you have owned it for over five years (and "owned" means the tapu has been in your name for 5 years+, not when you agreed to buy it or when you paid for it etc - the date is taken from the tapu) then there is no capital gains tax to pay when you sell it in any circumstances. You will have to pay property purchase tax on the property you are buying, the length of time that has been owned by the vendor is not relevant to this tax payment. There is no possible arrangement that will result in you paying no tax - you buy a new property, you pay property purchase tax - no exceptions I'm afraid.
The prices on the tapus is not greatly relevant these days - the amount you will have to pay will be set locally, not based on what the value as stated on the tapu.