I don't drink coffee, but I suspect it is a justifiable expenditure. Coffee drinkers, would you say that drinking coffee makes you, say, 15% more productive for the hour after you drink it? If you gain any productivity benefit, is it due to something about drinking coffee, or something about not not having had coffee? (The second question isn't relevant to this discussion much; I'm just wondering whether I should start drinking coffee myself.)

It doesn't make much sense to look into expenditures that are small, sporadic, and that you suspect make you feel better. However, it does make sense to look into an everyday expenditure if is big, regular, or potentially useless. (For example, if you generally buy a new pair of shoes every month or two, that's definitely worth looking into--it fits all three of the criteria.) You can frame cryonics expenses as small and regular or big and irregular, but either way they trip one of the criterion. (Coffee expenses are also regular and therefore worth looking into, but as I explained above, I think they might be justified.)