https://forums.collectors.com/discus...ss-psa-10-sets
There is a reason that the guy in the thread above (who claims to be going for all PSA 10 sets throughout the 80s and various manufacturers has never actually sent one of his "raw gem mint" cards in for grading. It's a completely money-losing proposition for these types of cards.
There are many times when a graded card will devaluate the card from raw. One is for mid-grade 50s-60s cards. Those are readily available in lower grades and while you might pay $8 for a nice looking NM card, if it is actually graded a PSA 7, it might not sell for $8. Same for cards with qualifiers like ST (stain), MK (mark), OC (off-center), etc. Many collectors will completely ignore nice cards with the Scarlet Letters of qualifiers.
Now there are millions of examples of PSA/SGC/BGS cards greatly increasing in price because of the grade given, but hopefully we've all learned enough in the past year that nobody really trusts these companies to tell which cards are actually altered, or can give them a specific, repeatable grade. As such, I've stopped submitting to PSA whereas I used to send them hundreds of cards in bulk each of the past five years. I am selling off most of my graded card collection because of how jaded I am with their response to being proven incompetent.
But a card is worth what it is once it is graded; your sunk grading costs are baked into the price of whatever someone will already pay you, and they won't be adding an additional $$ just because that's what it cost you.