Maintaining a gitlab instance, a mattermost instance, a kubernetes instance, an elk instance on a cheap VPS provider gets you in a pretty good place for very little money. Your internal tools won't need much attention until you hit a higher number of employees.
Also with three employees you can still get away with a lot of free stuff (eg. a discord or matrix server for chatting, private GitHub repos)
Cost of cloud solution is not comparable to cost of employee - employees build what you want, while on cloud you adapt to the solutions offered and also have to do additional cloud-related duties not relevant to your problem scope (so you payed also for the stuff you don't need).