Advice seek for 15300 vs 15400 (white/black dials)

[otoro]

Hi I'm new member to the forum. My apology in advance if this question/topic has already been covered (although I did search past threads for this).

I'm currently on serious search for secondhand 15300 or 15400. 15202 is on my peripheral radar but that would bust my budget and result in several weeks instant noodles as opposed to regular meal.

Been doing some research on this the the biggest red flag I noticed are movement reliability and fragile nature of the aforementioned AP models (in comparison to my current Rolex BLNR).

Please allow me to break down my question by the number:

1. Dial color. The blue/grey dial is obviously the most popular AP dial colour and retain best resale value (often times 15-20% higher value than the other two colours). After that which one come next...white or black?

2. Size. Strangely enough I never measure my wrist size. I can comfortably pull off my 40mm Rolex BLNR and even my previous 42mm Rolex Explorer II. Would 39mm or 41mm fit me better? For that matter, which one do you prefer?

3. Demand. Which one is easier to resell on secondhand market (15300 or 15400) while retaining best value?

The two potential purchase in front of me:

15300 white dial. 2010. Never polished nor service. Since it's at that 5 years milestones, I will likely need to bring it in soon? From what I'd read, the servicing would cost around $1k USD? The asking price is $11,000 USD with box/paper.

15400 white dial. 2012. Never polished nor service. A year warranty left? $13,000 USD with box/paper.

Thanks in advance for any advice and glad to finally join this forum after years and years of lurking.