For enterprise software it makes sense to leave off the pricing since you usually want to structure the pricing based on their needs (AKA charge more for big clients).
But I don't agree with your premise regarding potential customers being confused or deterred from signing up. Granted, if you have a very complicated pricing plan it can be confusing. But if you have a straightforward pricing structure that's inline with what the market expects, then there will be no confusion. And forcing a sales call would actually lover conversions.
But in the end it all depends on the the specific market. And as usual, the ultimate answer is "A/B test it".