FWIW, I'll offer my understanding as someone who dabbles in collecting books, comics, magazines and all kinds of other ephemera. Marvel Comics #1 (either Oct. or Nov.) is an incredibly rare comic. I would guess that there are somewhere between 200-300 copies still in existence (although that could be off +/- 200 copies). This differentiation between the 2 months has been known for some time but everyone still considers either one to be a "first edition". Conceivably, the November copies are "second printings" of the "first edition". In any case, both printings are so rare that any delta in the price valuation between the two has traditionally been negligible. Condition has been a far greater factor in setting the price. Traditionally.
However, as someone who has always considered this to be the grail of comic collecting (yes, I'm old school), I'd be overjoyed to own any copy and would probably follow tradition in my own valuation. Having said that, if I had a choice between 2 copies that were essentially the same grade and the only difference was that one was an October and the other a November, then of course, I'd choose the October- IF the price was the same. What is that premium worth in dollars to me? Maybe 10% more. Probably depends on grade.