Market Tolls For Adventurers?

On page 143, it says that adventurers going to a market to buy or sell should pay tolls. Should I apply this when the PCs go to sell their treasure and buy basic equipment, or should it only apply when they're on a mercantile venture?

I'm not an autarch, but I've always only interpreted this in the context of mercantile ventures, which I believe is the intent.