Ricardo
If you don't have the time it is not worth it. However if you do it's totally worth it. I usually make anywhere from 10-20 profit (kop for -100 sell for 120+)which isn't much, but its a good way to support my addiction

Srsly, if you really want to maximize what you get for the item, you have to take the time to take really good good hi-res pics ( the more the better). This task alone can take hours. Its a pain in the ass, but it'll definitely help increase your final sale price. Providing a very detailed description is also another time consuming task, but trust me it works.
Final verdict. It's only worth it if you have the time and energy to invest.