The PRIMARY reason for why people expect that is because it, hum... Makes absolute sense since it's how it works in real life? I mean, at least that's what experience tells me. I mean sure game-world unnatural things like infinite income of money and infinite natural resources and levelling people and whatnot might bajoongle the market but at least THAT assumption is something that is eternally true, the price of the materials together will always be lower than the price of the finished product.