Late to the party but definitely not worth it. The hydraulic stick saw uses hydraulic fluid as bar lube, so in order for it to be non conductive you need to run the special hydraulic fluid which costs about 4x as much as AW46. It would be like running a gas pole pruner with two pressurized garden hoses attached to the motor. You cannot twist and turn it with your hands and arms, you need to swing your whole body. That gets old real quick, which is why line clearance guys make such lousy cuts.
The reason you found it for sale cheap is because nobody wants it. For $500 you could pay for 80% of a Stihl gas pole pruner and be ahead of the game. You would use the hydraulic saw once or twice and then put it up for sale in a year, looking for some sucker to give you $500 for it.