I agree with coppercoins, in that you just can't save coins out of circulation and expect much of a return.
My example is .. last year I bought a collection, paid over $12,000 for it. I was told that the collection
was put together prior to 1980, when the person I bought it from got it from his uncle that had passed away.
$3,200 of that collection I turned into the bank. That $3,200 consisted of Kennedy halfs,
Ike dollars and older but well circulated currency. If that same money had been put into a CD, it would have easily been double and good chance it would be quadrupled
On the other hand if you were selective in putting away coins .. and guessed right .. there could be a chance you could come up with a nice profit .. It would be easy to see what you should have put away for the last 20 years .. much much harder to know what to do for the next 20.
To me there seems to be one area that has always done well.
That is in a coin series .. that have a large collector base, in the high grades.
I think you have to exclude coins that are sold from the mint. like proof and SMS coins.
While there are some in this category that do go up in value, it is more of a gamble
because there are just as many that go down in value.
The ones that go up the biggest percentage are business strike coins in grades MS 66 or better.
This applies to the popular series like
Lincoln Cent,
Jefferson nickels,
Kennedy half dollarsand yes ..
Washington quarters. New series like presidential and
Sacagawea dollars are more of
a gamble but so far are selling at good prices in the higher grades.
The tricky part is to have good access to uncirculated coins when they first come available.
Like bank wrapped rolls. Then having the ability to pick out coins in the higher grade.
Most people (including me) find it hard to determine if a coin will grade MS 65 or MS 66
and higher. Now once you get coins like this, higher grade, they do sell higher, but not as often.
meaning there is a smaller collector base in high grade coins then there are in mid to low grade coins.
So you may have to sit on them much longer. The con here is,the price you have to pay to have a coin slabbed. The jump in price and population can make it a win or lose situation. You may need to get a
grade of MS 67 or MS 68 to get into a good value, but your coin comes back MS 66.
But then there is still ... no one knows what life will be like 20 years from now.