Rare Coin Investment

I do believe that collecting rare coin can be one of the investment that making good returns. But I am wondering how and what shall consider before go into this investment. The very first that come to my mind will be how am I going to reach the buyer when I decided to sell. Collecting is one thing but for me the most importance part will be the selling and the earning part.

I heard from my hubby that his boss is a rare coin investor. Maybe we can get some advice from him as long as he wiling to share his investment experience. But the thing is, will he think that we are rich enough to invest on such 'high class' investment? :P