Welcome back to Subeta! All of the quests are great for making sP, which I'm guessing you've discovered already

Wizard tokens can be sold, I did when I was first new because I wanted sP to buy wearables :P But tokens can be used at vending machines, the token shop (there's newsposts roughly once a week when the TS restocks, and you can grab some nice items there), there's a couple of other features that use them, such a the Pet Zapper in Darkside, but I'm sure there's others I'm forgetting :)

I'm not super sure about the 'Price Today', there might be some cache issues with that but I've never needed to use it so I can't say exactly what is up with the pricing. Sometimes I think if the items are newer, they may have been sold at a much higher cost and the average is probably affected, but I'm not sure if that's 100% what happens.

Hope that helps a bit n__n

Useful Links:

What to do on Subeta? Useful general information for newbies Finding friends (Chit Chat) SubetaLodge (Offsite item database, pet colours etc.)
FAQ