The link will run underground from Scotland to Anderby Creek in Lincolnshire, National Grid says.
Both suppliers have said the increase is due to higher global energy and gas prices.
The deal would see one million tons of natural gas shipped annually from Canada to Germany by the early 2030s through a proposed terminal in British Columbia.
Scottish Borders Council is advised to oppose plans for a 12-turbine wind farm in the Lammermuir Hills.
Experts say action now can save money when the pinch comes this winter.
Typical annual household bills will rise by 13% when the new energy cap takes effect on 1 July.
A household using a typical amount of energy will pay £221 a year more, under the regulator's new price cap.
The Mark Hill project would be next to the Penwhirn site which serves many nearby towns and villages.
All existing tariffs will be honoured in full under a planned deal that could create one of Britain's largest energy suppliers.
