So, I am a relative newbie to Civ V. I've been playing from the bottom up in terms of difficult level. I'm trying out my first game on Prince right now and the trade AI has suddenly changed noticeably. On Warlord, other civs will pretty much always trade you one-for-one for luxuries if you have what they need and vice-versa. On Prince, it's almost impossible to get them to give up luxuries. Every time I try to trade them a luxury they want, all they will offer is like 2 gpt and maybe open borders. They won't trade a luxury at ALL without accepting at least THREE luxuries in return. What gives? Is this just how trading works at Prince level and up? Are there any recommended approaches to trade for luxuries? Thanks!