DAC cost claims: which assumption do you check first?

For direct air capture, the headline cost is never just a cost. It carries an energy price, plant lifetime, sorbent lifetime, heat source, financing assumption and usually a storage assumption too.

Keith et al. give one very concrete process case (doi:10.1016/j.joule.2018.05.006). Fasihi et al. are useful for the techno-economic spread (doi:10.1016/j.jclepro.2019.03.086). Sorbent degradation is the thing I see under-discussed in quick claims: doi:10.1002/anie.202302887.

When someone says "DAC will cost X per tonne", what is the first missing assumption you ask for?