My goal was to say search for nice examples with great wrist presence just under the 9 scale in the 8 to 9 range. You can easily jump 25% in price going above the 9 scale as in 1 to 10 with ten being perfect. When you get above 9.5 perfect lume flawless black dial unpolished the price is double very quickly.
As you grow and refine your tastes you can take the time to find your perfect match but most people set the target at perfection but want to have a bargain. And with the target set so high never pull the trigger.
I am not sure i understood the question on serial numbers.
Bill