Spiderman was first popular because of Marvel comic books and they remain so popular that an eBay seller with the ID of “highgrade60s” has found it worthwhile to put a banner on eBay advertising his collection of Marvel comics.

The sales of vintage comics is thriving, at least partly due to a new "grading" system. In the past, collectors were wary about buying old comics, because it was so easy to be cheated.

The only established comic book grader is a Florida company, Comics Guaranty LLC, or CGC. The grade is a 1-10 scale. This grading system has given new life to the vintage comic book industry, because collectors can feel confident about buying sight-unseen magazines. Some recent sales of Wonder Woman show the popularity:

* Wonder Woman No. 115, graded 9.2 by CGC, sold for $1,007
* Issue No. 122, graded 9.4, sold for $1,005
* Issues numbers. 127 and 128 sold for more than $1,000

According to the Comics Buyer's Guide, these four issues aren't particularly rare, or didn't have significant new characters. Instead, the prices are indicators of collector confidence due to the grading system.

There are even sites that analyze CGP books, like gpanalysis.com,and they help establish a more honest market for comics collectors and sellers worldwide. According to their stats, so far this month, 6,224 comic books have sold, for a total of $1,846,020.88, and the highest priced book sold for an amazing $47,150.

So, if you're a comic book fan, head on over to eBay and get involved.