I got an education in selling

Read your own words Jason - they explain perfectly how and why dealers can make a living with coins. So when you can do the same thing they do, then you too can make money. Until then, things will remain as they are with you losing money.

For as long as I can remember I have said that the buy/sell spread (dealer vs collector) is between 20-40% depending on the coin. And in some cases (low grade common coins) it is even higher than that.