Coin collecting in the unscrupulous world of coins, and dealer fraud.
First there are a few things you should know. eBay is an auction house community, and
All sellers, are not created equal. Some coin sellers are down right dishonest, dealer practices, and lack of ethics have made it difficult for the buyer to know whether, or not they are getting a fair deal.
Nobody wants to get taken advantage of..
Some advice, always read the entire listing before you bid. Some Coin dealers, but not all are among the most dishonest, unethical people in the world.
They will deceive you with there doctored photos, tricky wording, and downright lies.

Some will emphasize on the grade. Ungraded coins are never worth what they tell you they are worth. If its their opinion on what a coins grade is, you should not trust them. Its very difficult to get it 100% correct unless you are qualified to do so.
In the world of coins, anything goes. Its a dog eat dog world, profit, and money runs there lives literally.
Chances are you, see dollar signs too. The greed factor will destroy you. Never assume you are getting a fair deal when buying raw coins, and only trust a few company's that qualify as third party graders. NGC, and PCGS are the most accurate  graders for coins.. Research values before you buy, and don't think because a coin is graded its worth the price reflected in a price guides. Do comparisons shopping before you buy.
look for similar coins that have sold in auctions before, be specific about the date, and  grade and the value that was placed on the coin, dictated by the market as a whole. I hope this has been a help to all you new, and old collectors alike.