If you saw the name for sale, would YOU part with real hard cash to purchase it anywhere near the asking price?
The value someone perceives from having the name has to be greater than the value of the cash they are parting with.
If the name cant provide that extra value, then it is unlikely you will find a buyer!
Nobody that I am aware of makes a profit on every name. But by buying quality names at reasonable prices, by being patient (one of the most necessary aspects of domaining), and setting fair selling prices (I see too many people who are more worried about leaving any money on the table rather than taking a profit, reinvesting that in a better quality name and moving upwards with a regular cash flow), it is well possible to make an overall profit on a group of names once all the registration fees and other costs / expenses have been taken into account.
Sure you will make mistakes but don't be afraid of that - you learn far more from mistakes than you do from successes! Show me someone who has never made a mistake and I will see someone who has not really done anything!
Have faith in yourself and your judgement, read everything you can, then just get out there and give it a go.
And concentrate on selling to end users, not to other domainers!
Just my couple of cents IMHO.....