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.