The cartridge is professionally produced, with open-source software and extensive documentation.
Limited edition pricing is $39.99 per cartridge, with a shipping discount for buying five.
For complete product information and the order form go to:
http://www.atarimax.com/
or directly to the MaxFlash cartridge page at:
http://www.atarimax.com/flashcart/documentation/
Highlights:

TRUE 8Mbit ( 1M Byte X 8 ) Flash design.

Entire 8Mbit flash space reprogrammable in-system.

Hobbyist oriented design, no surface mounted parts.

Highest quality color labels.

Easily create and share your cartridge projects with anyone.

Supported by the same open-source perl/6502 development kit as the 1Mbit cartridge.