GMT - G serial or random?

[bofon13]

I would apreciate your help, so please give me a piece of advice on this:

I am now looking at two watches, both new, with box and papers, but one is a cheaper G serial and one is a more expensive one random serial.

Would you pay more for a random serial? Are there any diferences between these models except the serial no? I know some of the early GMT had clasp issues... Is the blue spring in both of them?

Thank you!