The main purpose of bundling files for download is that they are compressed to save bandwidth. The Sony LRF files are already compressed and even Harry who provides his books zipped does it for system compatibility rather than size.
Given the great diversity of titles and subjects offered in download at MobileRead, any combination of titles might include a fews that some people would not want to download or read. For example I would most likely have passed on a package of 14 volumes for the Haggard Anthology but easily downloaded the 1st and read it. (I posted very little until I finished all 4 books in it.) Then I downloaded the remainder of the volumes.
With the sort features of the ebook list it is easy to find the rest of a series or other books by the same author. So you have your choice -- take them as they come or pick them up when you're ready to read them.