Yeah its never smart idea to buy when price is high as it will kill your profits and its always good to buy when price drops and sell them when price goes higher and that is the best way to make profits and most of the traders are making profits in the same way.
That's everyone thinking about profit, buy at low price and sell at high price. But, the hard thing is when the best time to buy and sell. Because, I have seen everyday got trapped by market and loss their money with blindly to buy without thinking about the future.