If you're talking about the Sata Vision 2000 (Part #36384) $500 is cheap. We can't sell if for less than $750.
If you're using an oil lubricated compressor to feed you breathable air you want to make sure it has a CO detector which will cost at least $500 plus you will need the proper filters on that line. This is why most DIYers drag around a second hose that brings air from a turbine because it cuts the cost WAY down and most systems are perfectly safe.
Sata doesn't allow me to advertise their products even though we sell them. If you need a Sata product call 1-888-485-5008 for pricing.