Why aren't there more groups posted? Some ideas.
Price: Groups are expensive; most of the posters here are on a limited budget. (

and just read Andrews post...)
Historical Interest v. Collecting: The convergence of the desire to acquire artifacts and deep historical interest is not common. A dedicated historian can lack the desire to “have” something “historical” while a collector can completely lack the desire to know any more than a cursory history of an artifact.
Historians like to read and talk. Collectors like to fondle. Does the twain meet very often?
Flaws: No one wants to find out that what they have is a fake. Yet verifying even a modest sized group is many times harder than a single piece; one is not only dealing with the awards but with paper and text. Even what makes a “complete” group is open to debate. Imagine that many aren’t interested in the hassle.
As well (and this applies to singles), there’s the “if I don’t know something is bad then I can’t get accused of knowingly passing on a bad piece in the future” factor. With the higher price and greater chance of a flaw in groups to begin with this becomes a bigger issue than singles. Hence people don't post what they might someday want to sell.
Comparisons: Groups that evoke interest in others typically have to be intense. Wouldn’t doubt if many hesitate to post “yet another mediocre group” after doing a bit of looking at groups that are already out there.
Difficulty: Research involves lots of time, energy and money. Even after that most of the folks here don’t read Russian, so even more is spent to get it translated. All that means fewer people doing it.
Fear: “Hi! I have thousands of dollars worth of portable and liquid items here. Everybody, take a look!” It’s been said that you should treat anything posted on the net as if you’ve put up a billboard along the freeway with the same information. So most folks hesitate to announce to the world their possessions. Groups are the Big Dogs of medal collecting, so it’s not surprising that many of them don’t make it onto the web.
Lurking: On any board the vast majority of visitors never post, only read.
None of this is certain, just thoughts and opinion.
Steiner: "Why do you want it so badly? It's just a worthless piece of metal. Look."