Should I sell my coins now or wait?

I realize many people consider coins a bad investment, and that many
of you here are into the hobby of coin collecting more than the
business of it.

I was told 2 years ago, "Don't invest in coins, they are not a good
investment". But I read some books and did some research and decided
that it made more sense to buy coins than it did to invest in stocks
or bonds.

So anyway, I bought about $4k worth of coins from ebay, mostly Morgan
dollars, a couple gold coins, mostly PCGS or NGC graded coins, a few
graded by other certification co's.

But here's the rub: according to recent price lists, my coins have
almost all gone up in value and are now worth about $6k as opposed to
the $4k I paid for them a year and a half ago.

Now, my questions to you kind folks are these:
1) Have most people made good money on their coins the past year or
so(i.e.; did the market generally rise in silver and gold collectible
coins)? Did I just buy at the right time, or do I have some talent for
buying coins, or did I just get lucky?
2) If the idea is that I want to make money on my coins, should I sell
them now (since the price is up on them) or is it likely to go up even
more, so I should wait?

I made the investment because I am trying to get money together to buy
some property. We are still a ways away from having enough money, so I
could wait if I thought the value of graded MS64 and 65 silver and
gold coins is generally going up. Or I could sell now and put the
money in stocks or an IRA or ???

Please advise. I realize no one has a crystal ball and so no one can
give a definitive answer. But I am just asking for an "educated guess"
from you people who have been around awhile in the coin game and
probably have some insight into the current and future market of
collectible Morgan dollars and St. Gaudens. For me, making $2k is a
great deal, not a small amount of money, and I just want to keep my
$6k in the place where it is most likely to grow, with not too much
risk. If it goes back down to $4k, that wouldn't be so bad... My
instinct is to cash out the $2k I made by selling some of the coins I
think are least likely to have good increases, and put that $2k into
the coins I think are more likely to increase.