I just had a look at some of mine.
I'd say on average, the audio folders are between 2 & 3 Gb for a typical 5 minute rock song (I don't do short songs

)
cwp files are between 2 & 3 Mb
My biggest project which has 75+ tracks, loads of synths, 100+ plugs is about 10Gb in total, but again, the cwp is an order of magnitude smaller (and this particular project took over a year to complete with multiple guitars, vocal harmonies, many, many takes, live V-Vocal clips - you get the picture - this thing is over 12 minutes long so the size doesn't surprise me one bit.