Is biology.SE the right place for asking about availability, manufacturer, review, accuracy of various demonstration models in biology? Such as human skulls?
Shopping questions are generally not a good fit for SE sites in general. The answer is likely to be outdated quickly, and the answer might also vary a lot on your location.
How problematic shopping questions are depends a lot on the specific market, e.g. on Photo.SE shopping questions about lenses seem to work pretty well as there is a very limited and stable selection of lenses. In such a slow market the usual problems of this kind of question don't really appear.
Another way to make such questions more useful is to avoid focusing on a specific recommendation, but instead to ask what one should look for and how to judge and compare different models. Such answers remain useful even if the actual models you can buy change.
In my opinion biology very often uses models, e.g. ecological models, genetic models. These are used in research, education, reasoning. I consider a mass produced plastic skull a particular kind of biological model, that may be of public interest and I would welcome questions and opinions about its strengths and weaknesses.