You could check ebay. Lots of people part out old laptops on there.
EDIT: I see you already found something similar on ebay, but I just did a search for " toshiba video card " (no quotes) and it brought up a ton of results, especially in ebay stores. You'd have to look through them to find the one for your specific system though. There may even be another model that is compatible with your laptop.
This is a geforce 4 MX 440 GO:
And it looks the same as the one nekro posted. Already has a bunch of bids and is almost $50...