I have to disagree with the last post. I've been buying coins for over 50 years. The so called "Red Book" is just a guide........says so right on the cover. By the time the current edition is published, the prices are 6 months old. You really have to see where the current market is. I have never gone wrong buying a "certified" key coin. That means certified by PCGS, NGC or ANACS. I've learned over time to offer one grade less from a dealer for an uncertified coin. Key coins of any series are still the best bet for any kind of investment (your going to keep these for 5 years or more). With that in mind, and everyone is mesmerized with the "Red Book", I only ever offer up to 80 percent for a key coin. I've walked away many times. Here is an example of what I have learned. This is what the Red Book has to say........1970 1931S Lincoln EF was $35.00. 2009 Red Book same coin $110. , Now look at the 1931D, in 1970 in EF it was $7.25, 2009 it's $10.00. Why? The 31S is a key coin. Today you should be able to buy an EF 31S for around $90.00. More people collect the Lincoln cents than any other series there is. Greater demand = higher prices.
Don't buy any coin unless your going to keep it for awhile. Nice to have a nice looking type coin, just they don't appreciate much over time. Bullion coins are tied to the market prices of gold, silver or patinum. By the way, you could have bought a 1877 Indian Cent in 1970 in VF condition for $285.00, today your looking at $2000.00. Of course we didn't have all the grade breakdowns we have now....VF20, VF30 etc. You could have bought a VF in 1970 and today may grade VF30 who knows. Doesn't make sense to by stocks based on 6 month old information, I'm sure that would be agreed upon. Same with coins, you have to have an up to the minute pricing available to you. My goodness as much as I hate it, Coin World is at least up to date on a monthy basis, and NGC provides info on current pricing. PCGS quotes only what PCGS certified coins are selling for, can't use that for raw coins. Most of all get to know your local coin dealer. Become a friend, talk with him. The more he feels your going to be a steady customer, you'll get better deals. I do mean get to know your dealer. I knew a few who ended up in the pokey for not to nice business dealings.
Enough of my ramblings......would like to hear what other think.