A lot of the actual info is what we call ‘FOIP’ (Find Out In Play).
That being said -
3 - 5 rings will get you a drink or a bit of cake in most camps. If you are getting a round in, there’s nothing stopping you from negotiating.
You get your resources - The prices on them do fluctuate, sometimes wildly. A general guide is 1 crown (20 rings) per resource item. Some are worth more, others a bit less. Herbs have a fairly wide range, and Mana tends to sit around 35r.
Those prices are a guide - Sometimes demand on something is really high, other times it’s low - Thats where you use your own skills in sussing out the situation.
It’s worth heading over to Brass Coast, and looking for the tents next to the Brazen Paradour pub… I can;'t remember what they are called, but they sell Sangria! Theres a guy there who sells a paper called the ‘Thrifty Squid’ - Which is a general price guide. Note that this can (And does) go out of date pretty quickly, as its printed between events and not updated during, but it’s still a useful resource. If you can’t find the dude (Beard, Golden jacket, Turban, horns, Happy-looking guy - Although that describes 40% of Brass Coast), Just ask around - A lot of bars, trading houses and groups might have a copy lying around although Traders will ALWAYS say ‘Ahh it’s rubbish, don’t go by that’
If you find yourself a little cash-light, sell your resources - Some bars will take the resource straight-up for drinks, and you’ll usually get the better end of that deal as they tend to be a little more free with drinks or OC stuff, Just make sure you know the rough value of what you have
Ask around your nations camp, There are a few ‘Big Traders’ and they can usually help you get on your feet if you want to try the trading game, or at least can point you in the right direction if you want your game to go elsewhere. Traders tend to know where various groups hang out, Where covens of rituals are, healers of each nation.
If you find yourself in Varushka, Pop into the Wulfen Reavers - They are really nice, but don’t tell them I said that. 2nd Legion in the Orc camp are fun to hang out with, A lot of the Brass Coast firesides are welcoming - House Tazeil for one. The Carta Nocturna in League are cool (Multi coloured drinks, easy to find)
But yeah, exploring and finding out what it’s worth is the way forward.