Sustainable farming can actually cost more to manage than conventional techniques in some cases. If ISO 14001 or another management protocol is utilized then apart from labour, administrative and reporting costs can be substantial.
For example a sustainable winery in New Zealand will cost a winery $550 per year and $375 for their vineyard. In addition, the extra time it takes to manage this system adds up to tens of thousands of dollars for the average winery.
The bottom line is whether or not any of these methods can produce a product that achieves a higher average price than their competitors.