After having collected coins as a young lad, I began collecting again in 1999. Just like baseball cards, I wish I still had the collection from my youth. My general rule is this I only buy NGC or PCGS slabs. Other companies I wont pay much more than 3-5 points below their grade or roughly what I pay for a raw coin.

To expand on my general rule, for silver/gold bullion eagles, only buy PCGS. The difference between NGC which is an excellent company and PCGS is huge. Just look at various auctions to see my point. For any other coins, NGC is fine. For the "normal" collector there is not any real significant difference in auctions. I am talking about coins in the $20-$700 range. With top end coins, I have seen a difference in the prices that are had at auctions.

When you are bidding check carefully who slabbed the coin. When I see someone is selling a coin listed as simply MS 64, I am on the alert. The reason for this that anyone who had a coin slabbed by NGC or PCGS will list that in the title description.  Be  on your guard when you hear people praising 2nd tier grading companies as being the same as PCGS or NGC.  No one really believes that.