As it says really!
Something that is:
1: As cheap as is practical, and
2: Worth having, and
3: Will tolerate pubs and back of estate cars.
I know nothing about DBs and I can't imagine that a bow will be needed, but after chatting with some mates about the possibility of all all acoustic bluegrass band I am now researching.
I have played upright a bit - I had an early NS Wav bass - but I will have to put the practice in to get somewhere near competent again.
ta