And... Arshad Bhai, only share the sale price If you feel convenient and comfortable, and / or, the other person is potential seller or buyer of that vehicle, and wants to have idea about market price of such vehicle.
Else if, IMO, its not a polite and nice gesture to ask others; how much you bought for? How much you sold for? Etc.
(No offense / disrespect to anyone, just my suggestion)