CGC comics refers to comic books that have been graded by the Certified Guaranty Company. 

CGC is a comic book grading service. 

Collectors mail in their comics to the company, or submit them at a comic book convention, pay a fee to have their comics graded, and then eagerly wait to receive their comics back. 

The CGC comics come in a clear hardened plastic case, along with a number from 0 to 10, a brief description of the condition, and information on the comic book itself. 

The number represents the condition of the comic book, with a 10 being a comic book in perfect condition. 

Since obtaining a 10 is nearly impossible, most collectors accept a 9.8 grade as representing a comic book that is in near mint condition. 

Collectors value CGC graded comics since the grading provides an accurate and reliable way to know the condition of a comic book.

You can check out values online, or by using the Overstreet Price Guide.

So how can you buy and sell CGC comics on a wholesale scale?

You can advertise on websites such as Craigslist. Your ads can explain that you are looking to buy and sell CGC comics. 

You can also search on Ebay for lots of CGC comics, negotiate with the sellers so that you can buy the lots at a lower price, and then list those lots at a future date, using better pictures and a nicer description. 

You could choose to wait to see if the value of the comic books increase, and then hopefully resell the comics at a higher price. 

Another source for CGC comics is a comic book dealer. There are many established dealers such as Koch Comics in New York, Neat Stuff Collectibles in New Jersey, and Gary Dolgoff Comics in Massachusetts.

These comic book dealers can sell you lots at wholesale prices, and provide you with a steady stream of merchandise. 

Once you have inventory, you can resell it to local comic shops, such as Midtown Comics in Manhattan, or New England Comics in Boston. You can also try visiting other local shops, as well as advertising and reaching out to international collectible retailers.