I think it is hard to say whether we are ready or not. We are assuming alien beings to be one thing or another based on stereotypes that come from scifi, or what people would generally expect from aliens. There seems to be the notion (including this very post we are replying to) that having a monetary system is bad. But... If having a monetary system is bad, then, how do different individuals interact with each other when it comes to offering or receiving goods and services?

Many ancient cultures had a barter system, and while these systems supposedly escape from the evils of money, it also creates a lot of other problems. I want two horses, you want five hens. But I don't have five hens. I have a pig. But you don't want a pig. What do we do?