Given my current interest, I would have to say dimensions first, condition second, grade third and only one gauge (12).

For the sub-set of Parker collectors (or Fox, Lefever etc.) that are condition collectors that never plan to shoot there guns condition is first, grade and gauge are tied for second in my opinion. In the long run they will most likely make out best from a financial standpoint. They get their satisfaction from owning mint or near mint examples and keeping them locked up in a safe. It seems the majority of Parker enthusiasts are collector/users that get their satisfaction from harvesting game birds and breaking clays with guns from the golden era of fine craftsmanship and plentiful game. These folks have much different rankings of what is valuable.