I sell. I need the dough to get something I want. This just jogged my memory. I've got one to sell. Maybe I'll see what I can do first at the Balto Whitman show next month.
I sell/trade the extras. Unless they're super beautiful, it doesn't do me much good to have two of the same one. Better to have two different coins Of course, any coin that was gifted to me by family I keep no matter what. Those have special history.
If it's a duplicate, and since my collection is based on "singles" (one of each kind in MS, usually by date)... then I sell the dup, eventually.
That depends on the coin and its value. Honestly, selling it directly to someone saves you the middleman fees. I think trading is best, personally. You can list your coins for sell on Coin Talk.
I wait until I finish a series that I am working on then sell off all of the duplicates to start my next series. I recently traded and sold off 58 proof Liberty nickels duplicates to start my large cent collection. Some of them were traded with friends or my local coin club members then a group of them went to one of our dealers here.
generally I accumulate for a while and wait for a gold rush to sell and a fire sale to buy. example, sold a lot of low quality silver from my albums when silver was $42+ and picked up some much higher grade for melt prices. The higher grade coins were really fire sale priced, since they would have been premium in a low price silver market but were then going for melt price. Sold all my 40% and war nicks and a lot of duplicates in the $44-$48 boom. Been picking some nice finds lately, a couple of nice Indian Head cents at the show in Long Beach, some mint & proof sets with $ I had from coin roll hunting. Its not really a fire sale right now but there are some good values if you are patient and pick your buys. I'm a pretty small change collector so, I play patient and slow. but then I get to savor the few transaction I do make all the more. A lot of my "duplicates" are coin roll hunting finds, and these I sell or trade almost all of. Again I accumulate a little until I see a deal. Really most of my collection came from circulation coin that was traded up or sold. Annual mint sets from the mint are the only thing I really come out of pocket for.
to buy First most fav coin show (Long Beach every year, and maybe one other) second brick and mortar dealer I found I like (1 1/2 hour drive away though) third place - here on CT (only because harder to see what you are buying) fourth Ebay-ne of my existence to sell 1 here on ct 2 ebay 3 dealer 4 coin show trade 1 dealer 2 coin show 3 here on ct I know I know... all mixed up. Kind'a like me? lol
It doesn't hurt to sell duplicates as it helps you add extra funds. That may help you purchase tougher coins down the road or towards your savings. From my experience, every time when I start to offload a bunch lot of coins, there is one coin that I have been hunting for a while that appear out of nowhere. I've been hunting some of them for more than 5 years easily!!! When that happens, I'm much happier to make a small loss on some of the duplicates that I have. That extra funds do help. That said, having duplicates do help in some ways. It helped me identify varieties, potential errors as well as counterfeits. There are some coins that I own more than 5-10 duplicates just to ensure that I know the design inside out. That said, it does hurt financially...
I've sold several coins on Ebay recently to make room for improvements to my collection. So far I am happy with the results, as it has allowed me to get back most of what I spent on the coins originally. For example, I just bought a nice Trade Dollar that is a big step up from the one I already had, so there is no point in keeping two of them. Ebay is my friend in this situation.
for me I am a common man collector in that I like circulated coins with natural color and signs of use in commerce. I find it difficult to sell off nice for grade or attractive old natural toned examples , they can be tough to find even among common dates. I do tend to sell or trade off extras in phases , I can let a bright white Morgan or Franklin go with out a thought. The 2 buck mercury with natural attractive tone is far more difficult for me to sell off even if I have multiples of a given date. Ebay is still a good venue as are some of the buy/sell forums I am far more buyer then seller though.