“And the hardware for a local cache of a flat file structure shouldn’t cost more than $1000 or so [and that’s for new equipment - used equipment would be essentially costless]. “
let me get this striaght... you want to handel teh volume of post on FR with flat files? are you insane?
If you're suggesting that they stick with the relational nonsense, then I'd question your sanity.
There is no known entity in all of computer science which is faster than a flat file structure, especially once it's been cached in RAM [and, better yet, cached at local ISP caching infrastructures throughout the nation].
Relational databases are death to efficiency.