Hi Gshawn and welcome to the forum!
Rick pretty much covered it all: the freebie grading which comes with membership in a grading service and, possibly more common, the overly optimistic submissions of raw coins in hopes they will grade higher than they actually do. Additionally, a seller who has had a coin come back from the graders lower (or considerably lower) than s/he had hoped will often just dump the coin on the market just to get rid of it and take the loss as a cost of doing business or the cost of the hobby. Many collectors want only coins of a certain grade in their collection. Still others will sell such coins because they suddenly need money and will take whatever they can get, even if it's a net loss due to grading costs.
Fred
Rick pretty much covered it all: the freebie grading which comes with membership in a grading service and, possibly more common, the overly optimistic submissions of raw coins in hopes they will grade higher than they actually do. Additionally, a seller who has had a coin come back from the graders lower (or considerably lower) than s/he had hoped will often just dump the coin on the market just to get rid of it and take the loss as a cost of doing business or the cost of the hobby. Many collectors want only coins of a certain grade in their collection. Still others will sell such coins because they suddenly need money and will take whatever they can get, even if it's a net loss due to grading costs.
Fred



















