I've had five of them... $150 is a pretty good price. One thing to see is if it's an older Curbow with the Mighty Mite pickup or one of the Bartolini ones. (Bartolini is better)
Being luthite, watch out for screws on this bass- like the strap holders. Very easy for the thread to get stripped in Luthite, so make sure it isn't wobbly.
Necks themselves should be looked at to make sure the truss rod is functional. For some reason, these basses when bought new, require quite a bit of tweaking to get the action low. Super low action isn't quite possible that being said, as the front body of the Curbow is curved- the bridge placement is on the lower side of the body curve. Strings will be on the pickup if set to extremely low because of this.
Sound is a little lacking on the low end and also still a little weak despite the Bartolini upgrade. The bass will also be hard to put on your lap if you're a big guy- but it is a comfortable bass, pretty nice overall but I would go for the newer Curbows with the two pickups.