Order of magnitude analysis is a useful tool to make better gut decisions in uncertainty.
In uncertainty, attempting to get detail and precision will be expensive and misleading.
But often if you can guess at the orders of magnitude of different factors you can do a good job picking between two paths.
List all of the possible costs that are a given order of magnitude.
Costs here also include uncertainties or unknowns.
Ignore any costs that are lower than the highest order of magnitude.
Multiply any costs of the same order of magnitude together.
Estimate the order of magnitude value you can expect.
If the order of magnitude of value is not at least an order of magnitude greater than the order of magnitude of the costs, the idea is not worth pursuing.
Another trick to reduce orders of magnitude of uncertainty is to reduce the time horizon to small time slices.
"If we take this small, obvious step, what's the chance it at least pays for itself? And what's the chance that there are further steps beyond it we could choose to take that might be good?"
If the answer to both of those is high, simply do it.