Note, this is a (net) carbon free lifestyle within a society that isn't (net) carbon free.
I'm not sure it helps to describe these as costs. Might be a better ad for their app if they framed it as accelerating the transition to saving money/civilization by directing consumer spending towards those working in the right direction.
I'm also not sure how options 2 & 3 (A second option is to purchase additional solar capacity in a remote solar park.) differ from just buying green energy. Guaranteed additionality?
