My own particular philosophy is to buy coins that I love to look at time after time. I don't buy to create a date run or collection of like things necessarily. To me, coins are historical art objects which encapsulate the history of the period, the talents of the designer and engraver, and the technology used to create them. I strive to find the most beautiful I can afford. I buy inexpensive coins if they catch my eye, and, at times, rather expensive coins (for me at least) that I feel have something unique or special about them. Because of the reasons I collect, it is hard to part with them. In comparison to buying, selling is difficult. One wants to have his own evaluation of a coin confirmed by others, so one strives to market high value coins in a way that exposes them to knowledgeable (and wealthy) collectors to the maximum degree. Of course, it's a matter of degree. My "expensive coin" is cheap compared to some coins in the US market where many sell for more than $100,000. We must all face the prospect of selling at some point or our heirs will do it. With rare coins, it makes sense for the person that knows where and how to market the coin to sell rather than leaving it to an heir who knows nothing or relies on an advisor who may not have the owner's best interest at heart. With low value coins, it probably doesn't matter. So yes, I would sell if the market for the coin at a particular time (such as the Chinese or Russian booms) made financial sense, but it's always hard to sell coins one loves.