Forum Moderators: mack
Such tools are for extreme amatuers and even in those cases don't really offer any geniune benefit.
Actually, it depends on what it is they offer... If by "website speed booster" they mean that they "gzip" the pages before they are sent to the browser, I would definitely consider that useful --not so much because of the money you'd save on data traffic, but because of the improved user experience: your pages may load much quicker (assuming the 30K is text; there would be little or no gains if it's mainly graphics).
Thenagain, they may mean something different altogether...
This speed boost works on top of any other optimisations you might use (like CSS based design or whitespace removal). Be wary of how they implement it though (IE5.5 has problems with some types of files if they are compressed.
Get as many details as you can from the host and post it here if you want further advice.