I don't want to spend a lot of money, but I'd like to pick up a decent 5-string. I don't buy into the mocking and derision banjos often get. I think they're a pretty cool instrument!
I think I'd prefer an open-back. What make one inexpensive banjo better than another inexpensive banjo.
I got a very strange clawhammer tenor Banjo from the Idaho Youth Ranch (unsure if they have them up North). It is labeled "Tempo", and appears to be from the 1960s, open-back, and probably American made. It was $65. The strange part is that the headstock has 8 tuners, sort of like a "banjolin", but it is in a tenor banjo scale. I believe it is like a 12 string to a 6 string guitar, so kind of like a 12-string-esque tenor. It is currently setup as a 4 string tenor.
Anyways, I believe the banjo type can depend on the style. Clawhammer banjos actually have higher action. I believe the resonator banjos tend to be more expensive then open back. I think it also depends on the hardware, wood, maker, and build quality, some of the same stuff that you'd look for on a guitar. I also believe it has to do with the construction. Banjos have rods running through the length of the head, and I believe (I could be wrong) they can have a second running perpendicular to the first reinforcement rod, thus making it more sturdy and valuable. I am not by any stretch a banjo expert or even a good banjo player. Hope this helps!