That gives the pricing for running compute instances on BlueMix, but at the moment there's no pricing for these Watson services, since they're free-while-in-beta. Presumably post-beta there will be some kind of charge per N queries, like the other out-of-beta services (e.g. the Business Rules service charges $1.00 per 1000 API calls), but there's not currently an indication of when that's likely to happen and/or the likely price range.