For a real cheap short scale banjo have a look at a Johnson - I have one in my collection and it really is a great little banjo. I also have a Gold Tone "Plucky" which is even smaller. Both play well and can hold their own in the company of other instruments. The Johnson lends itself to a variety of styles and particularly suits my own thumb and one finger picking style which I developed because of medical condition with my hands.
As I build the occasional banjo, I was able to set up both of the above to my own preference so its worth looking for a bit of assistance if you do purchase one.
Good hunting
Pete