What's the amount you usually invest in something?

[Heatman]

When it comes to investing into anything, from a company, to a startup, to a new product, etc, what's the max limit you usually invest in that project? or do you invest differently each thing you invest in?

The money which I set aside to invest in a project is directly dependent on the kind of project I will be investing money into because if it is something that is too risky, I will not even be interested in investing any money into it.