Paying several thousand for the convenience of not having to yank my arm off is exactly what I was trying to avoid.
I used to work for a place that bought cylinders, we bought them in bulk, but paid about $100 per cylinder, (remember these are a steel tube, a steel rod + some O-rings).
It only cost $250 to replace a hydraulic pump for an outboard lifter. The CHEAPEST hatch lifter I've found so far is $2,200.00.
I would rather jury rig something. A hatch isn't a rocket.