It does seem a bit high, but often with these things you are paying for step size (how fine it can space cuts), speed, accuracy and tolerance, and cutting beam width, which might (or might not be) narrower on a 40W compared to 50W beam.
Frankly, I would feel more comfortable buying from MicroMark than a third party on e-bay, but I'm not sure this much price difference is justified. Have to study the details to know if theirs is exceptional in any way.
