The economy has been overhauled to make the Speech perk tree more valuable. In general, you'll find that your items sell for significantly less gold and most merchants carry much less gold. If you want to be a loot goblin and make loads of money, you'll need to perk into Speech so that your sell prices are better and merchants have enough gold to actually buy your stuff.
Vendors also contain a better variety and inventory of items to buff the buying part of Speech. Many merchants also have a specific peerless level enchanted item (though these are more expensive than items that would be found at a merchant randomly).