Cheap Genesis flashcart?

[Grandmasterjimmy]

Is there a cheap Genesis flashcart? I don't want it for pirated roms, just a hacked copy of Sonic 1. (Sonic 1 Megamix)

Also, hard hard would it be to replace the eprom in a cart with a new writable emprom.

The cart needs to hold about 2.5mb to 3mb. (Megabytes, not Megabits)

The only flashcarts I could find, are like $100, and the home-made ones don't hold enough information for the rom I want to use.

Also, it needs to support sram saving.