No worries! I don't know much as the economy goes as a lot of people are in the Discord and probably make trades there, but I usually gauge on who else has things up.
Greylings and Chars are fish you can grab from the level 35 fishing area. I typically use Koda alongside my regular fishing, so there's a lot of fish to pull in. Do keep in mind once you reach level 50 that the fish you gain from Koda are from the last area, so you're missing out on a
lot of cooked food.
Storks and Oxen are companions obtained at the profession level events in Black Hills (Icerun Sword Area 2) and Murkwood Den (Murkwood Sword Area 2). They require certain fish and bars respectively to gain, and they're locked behind a profession level.
As for pricing, it really depends on the item! Some items go for more- I've sold single Chaosium nose rings for 1 MS quite often, and I've sold 30 flour and honey here and there for 1 MS. Fish for the fish platter (Chars & Greylings, there are 4 in total) sell quite often because people need the resources! Another way to make money is to farm the first area in Goldsea (though there's no wild wolf encounters) once you have the "Find Ingredients" encounter unlocked for cooking (Oh, you can see these encounters underneath the individual area if you scroll down). Salt, pepper, yoghurt, and milk all sell well. Items that are used to make complex recipes and more importantly salt & pepper are used in recipes that the gardener takes. You can also buy these items in the mole market when they come around, and they sell for more in the flea market due to the high demand.