Parents have criticised a cinema chain, claiming it is almost doubling its charges depending on location.
A family of four wanting to watch a film in Carmarthen's Vue cinema would pay £34.16, while the same tickets in Cardiff would come to just £19.
One parent labelled the discrepancy "unacceptable" and claimed it was because of a lack of local competition.
Vue said discounted tickets are available to its customers on Mondays, Tuesdays and Wednesdays.
"It is ridiculous prices in Carmarthen. You could even pay to go to Swansea and watch it cheaper," said mother-of-two Anna Caroline Bowen, from Pentre-Cwrt in Carmarthenshire.
In south Wales, Vue has cinemas in Carmarthen, Swansea, Merthyr Tydfil, Cwmbran and Cardiff. Its only other Welsh cinema is in Rhyl, Denbighshire.
The campaign group Ms Bowen belongs to has compared ticket prices for Vue cinemas across south Wales and found that the cost for two adults and two children to see the film on Saturday was at least £11.20 more expensive in Carmarthen.
On Tuesday, Vue Cardiff was selling the tickets for £19, which is £15.16 cheaper than the £34.16 Carmarthen Vue was charging.
"We love going to the cinema and we are fully on supporting the cinema, but we are not paying double the price to go there, we can't afford it," Ms Bowen said.
"If they lowered their prices, they would get a lot more people going to the cinema and supporting them."
Ms Bowen believes the cinema has higher prices in Carmarthen because there is not as much competition.
"It is not fair and we are all realising now that all the prices are going up and up and up, and it is not acceptable," she added.
A Vue spokesperson said: "Vue Carmarthen customers can take advantage of premium big screen entertainment at discounted prices with Super Monday ticket prices at £3.99, Mini Mornings for £2.49, two cinema tickets for the price of one every Tuesday and Wednesday with Meerkat Movies, and Senior Screenings for £3.99."
But for Ms Bowen, this misses the point.
"Parents are at work and they want to go in the evenings, on Saturdays and Sundays but there is never any deals on at those times," she said.
"I understand the weekend is their most popular time but paying double everyone else? That's absolutely crazy."