At the 2K mark I think the obvious contender for me is the SMPc - used examples crop up on SC around the 1750 mark and dealers normally price them around 2.2K. Like your comment about the Quartz, a perfect intro into 'posh' automatics.
For the 4K mark agreed it's a bit harder - I think a titanium PO or PO chrono would be achievable and a strong shout. The chrono is way too big for me but hey, you can use the pushers underwater!