Well, judging by that "I've got a small number of extra gold units" part, I guess it's safe to say that he isn't one of those people, who's ready to spend a sum, comparable to a budget of a small African country just to get a bunch of units (besides, such people can't possibly have a problem with silver fodder). And for normal players it's a common rule - to get the most of what you can from the what you can get.