And it was tried by Omega as well - see the auction results of the Omegamania auction!
The difference is: PP has manufactured far less than Omega, so the PP market is small and this rises the prices.
Omega was not as successful as PP - prices went up on rare pieces but the "wide offers" did not really move as there are plenty of Constellations, Seamasters, Speedies,... fantastic watches but far tooooo many on the market...
That is the difference with PP: they built about a total of 4500 watches a year in the past 1930 - 1960ies with a rapid change of models - so there are 500 pieces or less of some references without any "limited edition" activity as seen on many brands in our days. Is a number of 2000 pieces really something limited for collectors?
Limited editions are pure nonsense if the number is not below let´s say 100-200 pieces.
PP does not need to produce l.e. (except some special pieces at special anniversaries) as the total output is a "natural" limitation. This makes PP a collectors brand as it was in all the past.
The thematic auction though was a clever marketing event to raise the interest in the brand - and it worked!!
just my 2 cents
erich