Storage required for Full feed ?

[fredbloggs]

Hi, I have been requested to size up a storage system for a news server to hold a Full Feed as follows :  28 days storage of non-binaries  3 days storage of binaries   Assuming that todays Full Feed is 300GB/day, and this will grow to 500Gb/day by the end of the year, can anyone suggest how much storage space will be initially required, and say, how much in 2 years time ? (I am aware that Dnews compresses the news so that 300Gb is not actually needed to store 300GB of news..)    Regards  Fred