These people have an auction 4 times a year and tend to have at least one Morley clavichord that goes for £300. Morley themselves sell them for over £4000. They're not very good (far too quiet)
I've had a Morley clavichord for nearly 40 years. I don't find the low dynamic level is a disadvantage - quite the contrary, in fact. Your ears need time - about 10 minutes or so, I find - to adjust, in exactly the same way as your eyes take time to adjust to the low light in a dark room. But after that you come to discern a remarkably wide range of dynamic level. Among other things, this is valuably instructive when returning to the piano, since you come to recognise that the relative is much more important than the absolute in performing dynamics. You do need to be in a very quiet environment though - you become acutely sensitive to the slightest ambient sound.
True, the Morley is rather cheaply built compared with some of the beautiful modern craftsman-built instruments: but with such a simple action, this is far less important than it would be with a piano. If you do get a Morley, it's worth looking out for the 'CPE Bach' model, which has a 63-note compass up to top g. This is necessary for CPE Bach's own works, which are really the core of the clavichord repertoire.
Incidentally, most Haydn sonatas, other than a few late ones, also work remarkably well on the clavichord. Not really surprising - most of them had already been written by the time CPE Bach died, and many of them before the completion of CPE's standard treatise on keyboard (actually mainly clavichord) technique. It's likely that in their early years the Haydn sonatas were played just as frequently on clavichords as on early pianos - perhaps more so, since there were more clavichords around. They
dont, however, work too well on the harpsichord.
Apologies for drifting yet further off topic...
Topic: Why is virtuoso playing such a focus here?