[nartz]

It depends on the service being offered mostly. Often, in b2b sales, its up to you to understand how much value your service will generate for the client, and how to correctly price that. For instance, offering a service that could double a clients revenue would be very interesting for them, and you could try to sell it as such. However, you will have to compete for others who may simply offer service based pricing.

Usually, the model amounts to becoming a preferred vendor or partner (value based sale) versus a contractor (contractor based pricing); more on that, if you value based price, often it means there is a symbiotic situation that needs constant communication and nuturing to ensure success, which brings you closer to the client.