Peninsula residents will gather at Umina's Caltex service station from 11am this Sunday, but they won't be there to fill up - quite the opposite in fact.
Organiser Dennis Brady says they're marching, for the second time in three years, to demand the big supermarkets charge fair prices.
Mr Brady says locals are having to make sacrifices to afford to fill up.
"I've spoken with a young girl who takes her four kids to playgroups after preschool, and she said she just can't do it anymore - it costs her too much in fuel," Mr Brady says.
"I've also heard from people who travel to do their business... they've had to drop business up north because they can't afford the petrol to get up there."
Mr Brady, who began the protest movement around three months ago, says it's now cheaper for locals of Ettalong, Umina and Woy Woy to drive to Ourimbah and fill up there.
Earlier this month, the Peninsula and Kariong had four of NSW's five highest average E10 prices.
While as of yesterday, there was a difference of 32 cents a litre between Peninsula fuel (148.4 at Shell Umina) and the cheapest fuel on the Central Coast (116.5 cents/litre at Metro Tuggerah).
The event will follow local MP and Shadow Minister for Better Regulation Yasmin Catley calling for an inquiry into apps like fuelcheck, claiming they're helping Coles and Woolworths collude to drive prices up.