The demand for quality Constellations is as hot as it has ever been right now, if anything I think Speedys have cooled slightly while demand for these has increased, with a massive market in Asia demanding the best examples being a major factor.
Its the reason so many redials and flogged out examples are selling for more than they should, and its the reason people are willing to pay over the odds for an opportunity to own a really nice example as it will still be vastly cheaper than turning to a dealer.
The key value of components vary between models significantly, but on a 2852 its the dial, there are far more good cases than clean original dials. On doglegs in particular, its case and dial in roughly equal proportion as the cases as so susceptible that even including the pool of dome dials there is a shortage of good cases. On C-cases there is a surplus of good dials and a shortage of good cases.
Movements are pretty plentiful, even in the event that you have one in really bad shape, I've haven't paid more than $150 for an entire 751/564/551 donor in ages, and non-chronometers can offer most of the parts at far less again.
The dogleg in particular is getting hot again due to Omega bringing it back in Seamaster form at $21,700 in gold, it's a beautiful case design that's for sure.
https://www.omegawatches.com/en-us/...axial-master-chronometer-37-mm-52253372004001