I know they said there's many shops catering for the nobles, but a lot of the customers eating the churros look like they're wearing regular villager/townspeople clothes... I think those regular people shouldn't be able to afford the churros that easily if sugar is that expensive, unless the shop is selling it for super cheap and eating a loss, or 5 people pool together money to buy just one churro to share.
Or did I maybe just forget if they said they can cut the sugar with other things to make the churros cheaper? They've been repeating that sweet stuff is soooooo hard to get and super expensive this whole time, randomly forgetting about it here feels weird.