Before spending money try Musescore - it's free! It's

Actually I use ABC notation in an ordinary text editor for the same reason as many Mudcatters: because most of the time I'm only doing single melody lines or simple harmony arrangements, but I'd try Musescore first if I wanted to do something more complicated than a two- or three-stave score. Also for me it's an obvious choice because it's multi platform so I can use it on a Linux system.

Oh, and it can do multi-bar rests!