I think there are two big differences with Willie Manson's bat caves (reflected in the price). First, they have a 3 dimensional design containing lampwork, and second, the facet is a labour intensive subsequent addition, rather than something made in the hot fabrication process.
I sold around 400 Strathearns a few years ago, many on eBay, including a few moulded stars of various sizes. At that time the stars sold for less than similar conventional domed weights (£12 to £25 for the stars, compared to £15 to £60 for the domed ones). I don't know what prices have been achieved in the last couple of years.