There is the gold standard grading company, PSA.

Then there are 2-3 other reputable companies, such as Beckett.

Then there are other fly by night companies that pop up from time to time who do the slabbing in their basement and are 100% worthless.

I only buy and sell PSA graded cards. I don’t even mess around with the 2nd-tier grading companies.

For the more expensive cards, hundreds, or even thousands, of dollars can be the difference in a half of grade. No sense in trying to save a buck and be a cheap-a-skate and use one of the lesser grading services..