PSA submissions for modern cards

[cardsagain74]

(Decided to post this here too, since my examples refer to just '80 on)

I have never submitted anything for grading before, but the time will likely come soon to submit to PSA. A few questions for those who have been through the ringer:

How do you manage the value tiers when deciding how much to pay to get something graded, and do you feel that the estimated tier that you chose for submission influences the grade you get? Especially when it comes to wondering if something pristine and valuable will get a 9 or 10, and how you can never really tell what they'll do.

A perfect example is a 2000 Bowman Tom Brady. PSA 9s selling for $900, and PSA 10s selling for at least $4000. If you have one that seems perfect, do you choose the higher value tier to submit, or let them charge your account afterward if they give it a 10? Might paying the high tier initially help get you a 10?

And for economy/value club, situations like my small stack of mint '89 UD Randy Johnsons. The 10s are now selling for more than $100, but do you really treat any possible 10s as beyond the "under $100" value pricing in a spot like that? And once again, could it influence how many 10s you get?

Any advice is appreciated!