I was coming in here too describe this math as well lol.
Worse still is your speed wouldn't even be that far and you still need to sleep and eat and stuff.
Youd be at this for a couple months at least.
It would be great to cover all your small purchases though.
I tend toward a bit of poetic tension in my group's scenes, so as their GM those dollar bills'd have to be pulled out of a pocket at a constant, challenging rate until they were at the stated number or something unsavory would result. A blockage, or even a reversal of their initial pressure? The pocket swells with unstable magics ready to burst, or the bills begin to force their way into the wearer's pocket-adjacent flesh, etc. Something to keep the party weighing the consequences of getting too wild with the wishes, but ridiculous enough to be worth the challenge.
I don't think that fits with the spirit of the item, and leans back towards the monkey's paw. What you have to do is make it sillier. If they wish for 100gp, they can take out 1sp from their pockets at a time. If they wish for a million gp, it's a random location each time.
Fair point. I may've been conditioned a bit from too many years DMing for oh-so-clever players who consistently think they can finagle a blessing out of a cursed item. 🤪 My reflex is to pressure the retrieval of said coins on an inconvenient schedule (ie. 24/7) and just when they think they've got that figured out, find an amusing way to remind the part-time legends of their place in the grand charade.
For instance, who knows what unscrupulous attention might be drawn to such a spectacle as an everflowing pocket? Might be as simple as a couple of enterprising urchins in need of a quick score, or maybe it's a bit more obtuse in its connection. When the gang is asked to investigate the curious affliction a young noble seems to have contracted on their recent visit to the same town (inn, etc.) involving coins falling out of their mouth whenever they try to speak...
The best way to handle it would be to stand on something on have them fall and pull the rest out with gravity. I think that'd work. Maybe into a bag of holding.
If you wished to be a billionaire it's 31 YEARS. At $1 per second. No sleeping, no eating, no bathroom breaks, no nights off. 24/7/365. Realistically you'd die before your wish came true. Billionaires shouldn't exist.