  As scientists living through a climate emergency, we have a responsibility to
lead by example, or to at least be consistent with our understanding of the
problem, which in the case of theoreticians involves a frugal approach to
modelling. Here we present and critically illustrate this principle. First, we
compare two models of very different level of sophistication which nevertheless
yield the same qualitative agreement with an experiment involving electric
manipulation of molecular spin qubits while presenting a difference in cost of
$>4$ orders of magnitude. As a second stage, an already minimalistic model
involving the use of single-ion magnets to implement a network of probabilistic
p-bits, programmed in two different programming languages, is shown to present
a difference in cost of a factor of $\simeq 50$. In both examples, the
computationally expensive version of the model was the one that was published.
As a community, we still have a lot of room for improvement in this direction.
