You do not need
a comparative advantage to be the best at something [FTFY] to enjoy the benefits of trade, nor does your trading partner. Even if you can do absolutely everything better and more efficiently than I can, it will still benefit you to trade with me because you do not have the option of doing everything at once. I may shovel well, but if I am also a pretty good obstetrician, it will probably be more productive for me to pay someone with fewer high-value options to dig.
If you were to start playing World of Warcraft right now, you could make decent money farming copper. The enemies are not gray to you, so you would not be the most efficient farmer, but people who earn lots of gold per hour are happy to give you a bit of it on the auction house. On a non-trade example, when I went back to Asheron’s Call with a fresh account, I financed several dozen levels by hopping a portal to a high-level hunting zone and scavenging a pack of trash loot that players left in their wake. If I had thought of it, I could have made a service of being the town-visiting pet from Torchlight, if anyone would trust a new character with their stuff/money.
The past weekend was Canthan New Year in Guild Wars. This is an amazing source of money for a new player. Offering to sell Lunar Tokens for 200g and Fortunes for 600g, I was deluged with buyers. There were quests that rewarded 25 Tokens, and the established players had run them in previous years; they were effectively level 5 quests that awarded 5 platinum. I financed my first set of prestige armor off those. If you could get your newb to Lion’s Arch, you could convert Tokens to Fortunes profitably (if slowly) playing Rock-Paper-Scissors.
An economy that is orders of magnitude above where you are can be daunting, but if you can get involved in it at all, the profits to be reaped are huge.