I'm a style nut and have looked at many collections of styles for sale. I've purchased one collection, "Adobe Photoshop 7 One-Click Wow!" by Jack Davis and Linnea Dayton. On the CD were over 800 great styles but more importantly they taught, in the accompanying book, how to look at, deconstruct, and create your own. I've given the book to half a dozen people.
When it comes to collections, the prices vary widely. Andrew's voluminous offerings of stuff for Photoshop and Illustrator are probably at the greatest value of numbers per $. He sells a bundle of two collections, 7,000 styles for $15. I've never been tempted as the styles used for the examples are awful.
http://www.graphicxtras.com/products/ps_bundles.htm
At sort of the high end, Human Software sells their collections of styles 500 for about $40. I'm not impressed by theirs either.
Frankly, since that initial purchase, I've never seen any collection I thought worth paying for as there are free collections galore. The Adobe Studio Exchange has thousands of great styles just for a start. Then Hatch's entire collection (formerly PSXtras is still available at WZ2K). They are a mixed bag with about half being very valuable in my estimation.
Having seen your other work,
ronmatt, I would look very closely at any collection of styles you offered for sale. I would expect them to be exceptional. The price point for 100 couldn't exceed $10, I'd guess, to find a market. How you would do that is the key. Usually people selling PS or Illustrator presets have a web site? with many varieties of presets offered. Good Luck!
8))