How many people lost their crypto-currency because the exchanges were written by people with no experience/training in development (or security specifically).
The counter-point is to buy in people who can do better than you can for less money. In other words, if a Developer can build what you need in 1 week for $1000 (in 90s money!) what would otherwise take you 6 weeks, are you saving money or wasting it? We don't always count our own time as money but it is if you could be much better placed to sell or market your business.