I order the 44mm space grey aluminium. I am most probably keeping the watch 3.
I'm upgrading for Series 3 38mm to Series 5 40mm. Trade in is only $70, and it costs $299 new. To make it more resellable, I could pay $99 for AppleCare+ replacement. Just like you, I'm probably keeping it as it's not worth a decent amount of money anymore.