There's no mention of the Night's Watch getting paid and most of its members would have been broke when they joined. So how does anyone earn money to fund drinking and whoring sessions at Mole's Town?
Q: I assume that the Night's Watch does not pay the Black Brothers any wages in coin for their service - they get their provisions for free, after all.
What I was wondering...how do the Brothers pay the whores in Moletown? Since they're not using coin, do they pay in naturalia filched from Night Watch' stores?
I guess some women so far north would choose such a life (given that life is relatively harsher than farther south), even if they are not paid in coin...
A: A lot of the Mole's Town transactions are paid by barter, certaintly, but there is coin at the Wall... not much, though, especially these days... (see following answer). Some coin comes north with the highborn brothers... someone like Ser Waymar Royce undoubtedly arrived well heeled, and I imagine families send gifts and such as well... and there's trade that goes in and out of Eastwatch...
How does the night watch pay for goods and services
Someone must bring goods to the wall. And they in turn get paid in whatever the watch has on them, possibly a ring, some gold. Maybe the watch pays in the goods they get from looting or buying goods.
Food and tools
Maybe they pay in food or tools. The people that they get the services from must need food and weapons, as well.
Maybe they pay from the money they get from their family or other sources
Some of the watch are from rich family, they might take that money and use that.
Members of the Night's Watch are not specifically forbidden from seeing their families, but they cannot leave the Wall without permission. Desertion is punishable by death. First Ranger Benjen Stark would often visit his family at Winterfell while representing the Night's Watch.
Men known as wandering crows, such as Yoren, travel around the Seven Kingdoms gathering recruits for the Watch, offering them escape on the Wall
These people in the above examples would have plenty of time to gather goods, so that they could be able to sell or give to the watch.
Maybe the members of the watch whose family can't afford to get "care packages" and other merchandise gamble with the richer people of the watch and get paid from that.
The watch might be paid something, the reddit links seems to think they are paid something. But in a comment by @Moogle:
......Everything they need is provided for them (clothes, food, armour, weapons etc.) and they renounce their families and all ties when they take the black, so why would they need to send anything back to them
So while you might retain the possibility of them being paid(which they might), this is a well phrased reason to why they wouldn't.
Also they might take the goods from the lands beyond the walls and from fallen comrades. They could be stealing goods from the wildings.
They also control a region south of the Wall known as the Gift, from which they obtain supplies and provisions. The region was donated to them by House Stark, the Kings in the North, at the time