I buy the bitcoin when the price is low. When the price is high, I will use bitcoin to buy some useful things.
Spending coins isn't just a happening when the price is staying at very high price levels. People have been buying stuff with Bitcoin since the value was just a few bucks. Something that was priced at $10 back then, was being bought at the cost of 3 or 4 Bitcoins. Now the same $10 will cost you just 0.026 BTC. It just shows that ANY time is the right time to spend your coins if you want to buy something.