I see for sale on ebay or other places coins that are graded but are not key or semi key dates andare worth less than the submission price. Why would someone submita coin that is worth less that the price to submit and then sell it?
Either the submitters think the coins will grade higher and/or are worth more than they really are. Or, they don't care - I know a number of knowledgeable collectors who don't mind spending fees on grading, which amount to a high percentage of the value of their coins.
Some folks will have coins graded just to have it in a matching holder for a set they are working on.
They could have thought it was a particular variety and it wasn't. Maybe they needed a few more coins to make up a minimum submission size. Maybe it was part of a bulk submission and was an low end piece. Send in a bulk lot of state quarters some come back low end and a few come back with high grades. If the high grade coins pay for the whole submission in effect the rest of the coins have a cost of zero and whatever you get for them, even at less than what it would normally cost to slab a coin, is profit.
And of course, there are a few self-slabbers (who will remain anonymous) who flood the market with overgraded common date coinage, covering not only the price of the slab but realizing a tidy profit as well.
most likely the companies that you've never heard of that make undersized slabs with unrealistic grades, etc. Also known as "Basement Graders", such as PCI, SEGS, ACGS, GCS, NTC, PNCS, TGS, etc. just like pi, they go on forever.
I wouldn't include PCI or SEGS in the basement graders category. Maybe not top tier but not basement either. OK maybe toward the end PCI may have been trying to get into the basement.
I agree, SEGS is not a basement slabber. They are even included on the blue sheet. In reguards to the OP, I know some of the bigger dealers send hundreds of coins in at a time for around $4-5 a pop. They get a big break for the volume that they do.