Do a google search for "site:net54baseball.com PSA BGS SGC" and click on some of the links there. The search function on this site is terrible.
Based on COVID and the new money coming into the hobby the last few years, all grading companies are slammed. SGC seems to be currently handling it the best, by increasing and decreasing their prices based on demand. The most corrupt while simultaneously being the must trusted grading company, PSA, currently is so backlogged (to the tune of like 5 million cards in their warehouse waiting to be graded) that it currently costs $200/card to submit to them.
And before you sink a ton of money into grading cards, especially if you're going to be collecting them rather than flipping them, read as many of these links as you can:
https://www.blowoutforums.com/showthread.php?t=1298835
https://www.blowoutforums.com/showthread.php?t=1297767