Keep in mind I am living my Playmo dreams vicariously through a 3 year old and we only got our first set (4444) in July, so there is only so much I can put on the floor without feeling like I am spoiling him.
Ha, same here on all counts (except the first set was 3185/3352 in October). It's nice to not be the only one in that boat. His/our collection also has a mostly vehicular focus so far, but no pirate ships yet.
Your fleet is lovely, and given your son's play focus it sounds like you're managing the pace of expansion very well.
I wish you good retail luck either in the US or locally. Chapters often sends out one-time, limited window (like, 2 or 3 days, often only in-store but sometimes online too) discount coupons or codes, but I keep noticing them in my email a day or two too late. Mastermind Toys had a 15% off all Playmobil sale + free shipping back in October, before I'd discovered this place, if it happens again I'll certainly post it.