When I buy a new book and log it into my database I mark it as “off the rack Near Mint” which correlates to a numeric 9.4. When I was younger I used Near Mint, Very Fine, Fine, Very Good, Good, and Poor, just the basics. As I got older I used (+) and (-) after each grade. Now I use a 10 point system as do CGC and PGX.
Every comic book I buy, I bag and board for its protection. The new book along with a backing board is placed in a designated comic book bag. The flap is taped shut and (the comic) put away in a box after logging it into my database. The other books, the ones I love and not necessarily of any extreme value (or value at all) are placed in a Mylar sleeve. This sleeve is then placed against a board and both are placed in a Mylite bag, again with the flap taped shut. This method costs more to do, but not as much as encapsulation.
I tend to look over a book never asking what the grade is (something I should start doing). I simply ask for the price and decide what the grade I think the book is and calculate what price I would be willing to pay for the book. I purchased Avengers #57 last year. I haggled with the price, received the price I wanted, but did I still pay too much? I sent this book to CGC to be graded and for a special signing. They graded it a 5.5, clearly I still over paid (but at least now it has Stan Lee’s scrawl on it).
CGC and PGX do not own comic books. They do not sell comic books, nor do they buy them. For a fee either company will accept your comic book(s), look them over, mark their defects, and grade them numerically, .5 being the worst (Poor) to 10 being the best (Gem Mint). They charge based off the age and fair market value of the book and not the final grade. A 9.8 modern age book costs the same as a 6.0 modern age copy.
Once these books are graded they are then encapsulated in a “slab”. This thick plastic protects the comic book and tampering is easily noticed. The grade of the book is only accurate if this slab is not tampered against. Tampering could be noticed by the cracking of the plastic or more noticeably still the peeling of a sticker placed over the top of the slap that has the title and grade printed on it. With the grade of the book intact, both buyer and seller can agree on the condition of the book, now the only problem would be the price. Each slab is a thick plastic securing the comic book safely in place against damage. But which is better? Should you use CGC or PGX?