Any search  tool is only worth it's salt when:
1. Your users are searching using half-decent search terms (i.e. looking for
"car" when you really want to know how to drive one isn't going to help)
2. Your content is tagged with metadata, etc.

I have seen implementations where Google was used to replace the search
functionality, but it's more trouble than it's worth (and a fairly complex
setup). Personally I would save the $250k, but a search enhancer to
SharePoint (like Ontolica or something that will provide  Boolean searches,
etc.) and train your users to be better citizens. Garbage in, Garbage out.
Doesn't matter what the underlying technology is.

In the SharePoint world, you can setup best bets so that if someone does
type in "A7F83" it returns the right document/site/etc.