AM29F400BT: Cheap Source, Buy Now!

Hi,

From which electronics retailer can I purchase this memory chip at a reasonable price? It comes from a 045 906 019 G.

AM29F400BT 70SC

Is there anything else compatible? I can't find a reliable source.

"Is there a chip in my engine control unit (ECU), and since I have a socket that allows for chip replacement without soldering, I would like to have some backups made of the different software versions."

-A2-D2