If you're a rare coin dealer, then Monaco Rare Coin representatives can help you with rare coin trading online, as well as help you find resources when you need them. You will be on top of the game and even see opportunities where you thought weren't there before! I believe that when it comes to something that interests you (and you want to make a business out of it), then you should do all that you can so that you will get the most benefit.
I don't personally know anybody who deals with rare coins (maybe because it is quite an expensive trade), but I have seen some shops that deal with them. In fact, just last weekend we passed by this shop that deals with rare money, and I must say I was intrigued! We didn't get to go inside though, since we were in a bit of a hurry. Next time, when we've got the chance, I'll definitely go inside! :)