I would say the star brand of Inflatables are white water worthy boats
Star does not have reputation that hyside, aire, sotar, marvia, nrs and other top tier manufacturers have .Star is a second tier manufacture. There boats new go for what first tier brands get used.
I belive for many priviate boaters star can be a viable cost effective solution.
$1,200 new for their IK is a joke, way to much for just a little more you can have a high quality aire or nrs IK.
$400 for a used star IK seems high but if it is in excellent shape it may be worth it., I have seen Aire Ik for 4-600 + on the buzz.
Keep in mind this is a used commercial boat...it is not likely to be in excellent condition.
I do not belive that star use c7 valves....I think they use a non standard valve ..but I could be wrong on that.