8 cm/min * 60 min/h * 1e-5 km/cm = 0.0048 km/h
If I’m not completely mistaken.
I’ll admit that the “1 cm tall” is guesstimated based on my memory of the snails in my garden.
The linked source also mentions that some snails can be up to ten times as fast as the typical 8 cm/min (0.0048 km/h), but those appear to be maritime snails, while the snail in the image seems to be terrestrial.
In my country we have a flat 25 % tax on anything sold to an end consumer (there are some exceptions). It’s often mentioned as the most important tax we have to equalise the economy and finance the welfare state.
The point is that, because it’s a flat rate, you end up paying more the more money you have. If you only buy cheap groceries, that 25 % isn’t a huge amount of cash, while if you buy an expensive boat or car, it becomes quite a bit. This turns out to be a great way of ensuring that anyone who wants to “live rich” pays a decent amount for it.