[Yen]

I haven't solved this for video games, youtube, etc. I'd be interested in a solution!

For disposable income purchases, we budgeted out income, necessary expenses, savings, travel, etc., everything that requires long-term planning. The surplus (a fairly small portion) we then divided out into a per-person, per-day allowance.

I use a simple Google Form to record discretionary purchases, tracking the results in a Sheet, to account for whether this discretionary budget has a positive balance.

This has the nice effect of translating dollar values into time values, and giving a reference point for trading off the relative hedonic value of small frequent purchases vs. large infrequent purchases.