Some are, some aren't. The original post was about a unique piece. Charles I unites and triples are not rare, nor are the Cromwell broads particularly so. The crowns et infra are common, but obviously desirable. The pricing on these is too high in my opinion, but as long as the number of collectors holds up there is not likely to be a drop in the foreseeable future. Cromwell 50/- pieces are a bit more exclusive as there are only 15(?) known, one of which is horrible and repaired, but the other 14 are ok.