I have an even cheaper oil suction syringe type (without the valves the Silerverline) and use to "pump" the oil into a separate container.
I just suck the oil out of the dipstick hole (500ml per stroke) and then remove the pipe and push the oil into a suitable oil container, repeat until all the oil is out.
On some engines its a bit difficult to get the hose right down into the sump with a 1cm diameter hose, so a little connection to a smaller hose might be worth investigating.
The Pela seems to be a good bit of kit, but obviously, more expensive and a lot more bulky if you want to store on a narrow boat.
I can bring my syringe in if you want to take a look..