The Culture is a post-scarcity society where most people "work" at creative or beneficial activities because they enjoy it and/or it brings status. But in Excession we see references to a "fabulously expensive" troop of erotic performers. Likewise there must be resources that are in limited supply, such as properties with the best views.
So is there money in the Culture? If so, how does it work?
Within the Culture money isn't used and most citizens have largely no conception of how money works beyond various truisms that are taught to young children about 'money implying poverty'. If you want something (within reason), you merely need ask for it. If it's being freely given you can have it. If that person says you can't have it, you can ask the nearest passing AI to make another one for you.
Money is a sign of poverty. This is an old Culture saying I remember every now and again...
and
Almost the only aspect of her new life that she adapted to without pause for thought was the total absence of money in the Culture.
That all being said, Tier (where the erotroupe are based) isn't part of the Culture. It used to belong to another race and was inherited by the artificial intelligences they designed to run the station. Various races are allowed to use the facilities and some maintain their embassies there.
As such, (not being a Culture world) money is still used to buy things.
This environmental diversity and the civilisational co-dependence it implied and intermingling it encouraged had been Tier's raison d'être, the very foundation of its purpose and fame for the seven thousand years it had existed. Its original builders were, perhaps, unknown; they were believed to have Sublimed shortly after building it, leaving behind a species - or model, depending how you defined these things - of biomechanical sintricate which ran and maintained the place, were individually dull but collectively highly intelligent, took the shape of a small sphere covered with long articulated spines, were between half a metre and two metres in size and had seemed to have an intense suspicion of anything possessing less of a biological basis than they did themselves. Drones and other AIs were tolerated on Tier but very closely watched, followed everywhere and their every communication and even thought monitored. Minds were immune to this sort of treatment of course, but their avatars tended to attract a degree of intense physical observation which bordered on harassment, and so they rarely bothered entering the world itself, sticking to the outer docks where they were made perfectly welcome and afforded every hospitality. Tier, after all, was a statement, a treasure, a symbol, and as such any small discriminatory foibles it chose to display were considered perfectly tolerable.
No, the Culture is a "post-scarcity" civilization where pretty much anything an individual could want is available on demand.
The author Iain Banks says in his essay "A Few Notes on the Culture"
In a society where material scarcity is unknown and the only real value is sentimental value, there is little motive or opportunity for the sort of action we would class as a crime against property.
While there is no monetary system this does not mean things don't have value, as Banks mentioned value can still be conferred for sentimental reasons - which one can infer covers things like artistic or cultural merit, artifacts or works that would confer "kudos" or social status to their owner or patron. To my knowledge Banks never goes into detail about how that value might be realised but potentially an informal system based on favours, social status and political influence might exist.
We see this to some extent in the novel The Player of Games, where the character Jernau Morat Gurgeh has accrued a high degree of fame and respect due to his skill at games, this social credit being the measure of his success rather than any financial or material rewards.
The Culture has no money. There are many other civilizations in the galaxy. Many of those do have money, and people from the culture moving there need money.
