Grading Baseball Cards - When grades rises card value?

[Oshadogan]

Hi everyone,

I'm a new guy on cards world and I'm trying to know a bit of dynamics. One of the things that I'm trying to understand is about when I should or not grade a card.
Since I only collect 1st Bowman Chrome Auto cards (generally #/25), bulk of that cards are graded but I already understand that grading a card can decrease a card value on market.
Lets try to explain my point of view:

I have a 1st Bowman Chrome Mateo Gil Orange Refractor not graded. That cards is value around 100$. If I have a 10 Beckett grade I'm pretty sure that card can raise the value to around 150$, but if I have a grade 9 PSA, maybe that card can't be sell by more than 75$.

- This is driven because collectors don't want to have graded cards bellow 9,5 Beckett? Or is more about cards population and the overall conditions of all 25 serial cards (a 9 PSA can eventually be the higher grade of a serial numbered cards).
- Collectors prefer Beckett grading instead of other companies?

I would appreciate some insights on this subject, and sorry if this is the wrong forum to post this tread.
I live in Portugal and I have to understand if I really can add value to my cards sending it to some grading company.

Thanks for you attention,

Hugo

[Oshadogan]

If someone can suggest some kind of articles to read or information regarding this subject, I will be please too.
Thanks