Again, because we picked out RICS valuer, and he was working for us, he gave us the top end of what he thought it was worth as we were selling, were we buying the rest of the share he would have valued it to the lower end, but he told me to never tell anyone that!
That's something I need to consider actually. In theory we could save up the amount needed to pay the 12.5% share we don't own in just over a year. Might be worth it just to save some hassle but it would limit the amount we could put into my partners Help to Buy ISA (as I originally bought the property on my own).