Air Plus Comet is an airline belonging to the "Viajes Marsans" turism group. Their main business is flying people in the marsans organized travels, that is why you don't normally find tickets anywhere, they tend to offer spare capacity, specially in low season. I don't think they are selling much capacity in high season outside of a full package. Probably is not bad, just take into account is a megacharter. Some things may surprise you. For exmple you may end up flying an Aerolineas argentinas plane....which belongs also to Marsans. Or you may be sorrounded by honeymooners....