I am thinking of adding this Audemars Piguet Royal Oak to the collection. It looks stunning with its trademark grey AP tapisserie dial and oblong rectangular-octogonal case shape. Plus, at $600, it looks like a steal. Other listings typically have it for around $5,000.
I think it might be a good complement to the more traditional octagonal APRO that I already have in my collection. Does anybody know about the history of this—what looks to be rarer—rectangular RO?