Most small and mid-sized companies do not ask whether they should test their security. They ask what kind of test, what it costs and what they will get for the money.
The articles below answer those in order: which testing approach fits your system, what a penetration test costs, and what an attacker can learn about you without touching anything.
They are written for owners and managers who have to decide, not for security specialists.
Read the first one before you ask for quotes, so you can compare them.
White box against black box: coverage, cost per vulnerability and when each one is worth it.
Real ranges by scope, what you get for the money and how often you need to repeat it.
Open source intelligence: the exposure an attacker or a business partner can find without any access.
Tell us what you run and what you are worried about. We will say plainly which test fits, what it will cover and what it will cost, before you commit to anything.