Is anyone familiar with "libib.com, a web based system that is way more affordable than "atrium."
I am not very helpful as I am not familiar with "libib.com" and that was your question. However, if you are looking for ease of use and very affordable (free) then consider LibraryThing.com. We have used it now since 2015 and have over 10,000 books scanned in and cataloged. It is an outstanding system, and for those needing to use something that is not difficult or expensive, we have found LibraryThing to be exceptional.
I am not familiar with "libib.com" but our library uses LibraryThing for our cataloging and checking in/out of books. Here is a link you can click (http://www.librarything.com/more) or if you prefer just Google LibraryThing . After you have your library on LibraryThing you can pay a very reasonable annual fee for their TinyCat (here is a link to our church library (https://www.librarycat.org/lib/IRCUMC). This gives you such a nice avenue for your patrons to view from the comfort of their easy chair and 'see' what is available in the library. We have had our LibraryThing account since 2013 and our TinyCat online going on two years now. It truly has been a blessing for us.