It is worth keeping in mind that how to defeat X is not well-defined. The usual method for circumventing the planning fallacy is to use whatever the final cost was last time. What about cases where there isn't a body of evidence for the costs? Rationality is just such a case; while we have many well-defined biases, we have few methods for overcoming them.

As a consequence, I determine whether to workaround or defeat X primarily based on how frequently I expect it to come up. The cost of X I find less relevant for two reasons: one, I have a preference against being mugged by Pascal's Wager into spending all my effort on low-likelihood events; two, high cost cases often have a well developed System 2 methodology to resolve them.

A benefit is that frequent cases benefit more easily from spaced repetition and habit forming. In this way, I hope to develop a body of past cases to refer to when trying to plan for how long defeating future X will take.

Examples of frequent cases: exercise, amazon purchases, reading articles. Examples of rare cases: job benefits, housing costs, vehicle purchases.