On the Paragon Initiative blog there's a post that suggests changing your thinking about security trade-offs, those concessions we make every day in the development choices we make around the security of our applications versus other concerns.

The theory goes: You cannot have perfect security against all possible threats all the time for free. Usually, we expect our applications to incur a cost (usually in terms of CPU, memory, or electricity usage) in order to be secure. It seems logically correct that, if you need more security, your cost must therefore be higher.

Fortunately, this is not always true! Sometimes, given a choice between two solutions, the more secure option costs less than the insecure one.

The article points out that what we think might be a "fair tradeoff" between two choices may only look as much on the surface. They give the example of random number generation and the speed involved in using the random functions versus the true CSPRNG in PHP 7 (or the compatibility library). The article also points out that even those in the security industry make these same kinds of decisions. Essentially they lesson they're trying to suggest is that trade offs in security are usually based on the wrong assumptions or a limited knowledge of the technologies offered.

And if you reach the point where you have to make a choice between a secure option and an insecure option that might be better by some other metric, make sure you actually document and measure this trade-off. You might find that the benefit of the insecure choice is negligible, and that you therefore should opt for security.