Yes they do indeed :)
Like wiki says: A rule of thumb is a principle with broad application that is not intended to be strictly accurate or reliable for every situation.
As a rule-of-thumb, only spend 10 - 15% max of the purchase price on a reno.
Buy for $250K - spend $25K max. You are trying to spend $1 to get $1.50 - $2 or $3 increase in val.
