You're right, before .90, you could sell for 50%. However, it was at the point where I could fund my entire economy well into mid-game simply by running my sov and champs around and jumping on goodie huts and quests, and selling the goods I couldn't use immediately. I'm guessing this is the reason that shops only pay 10% now. However, I do find selling at 10% to be kinda pointless, so it would be nice to be somewhere in the middle.
There is a spells button in the lower-right part of your screen which will open your spellbook. Locate the spell you want to cast (there are multiple pages of spells), and click on it. You may be prompted to choose the caster if there is more than one capable of casting the spell. Then click on the target of your spell. For lower land, it is a little annoying, because the spell only affects one tile, so to get across a mountain range, you'll have to cast it 4 times or so.
