Tickets to see Indianapolis beat Washington 30-13 on Sunday went on sale in July at £79-£245.
But the NFL then dropped prices twice, in late August and again last week. That meant some fans who paid £185 were sat next to fans who paid £79 a few days ago.
Some tickets were also discounted or free via the Blue Light Card and Tickets For Good platforms.
Matt Cullen has travelled from Cambridge to most of the London games and said there were two main reasons for the slow sales; a price hike and a season-ticket package being scrapped.
“I find the prices now mind-boggling,” he added. “It’s so far above the rate of inflation that it just feels like a money-grab. It’s priced out a lot of long-term fans.”
In 2019, tickets ranged from £55 to £125. According to Ticket-Compare, UK inflation has since risen by about 32.4% and the cheapest NFL London tickets have risen by 43.9%. The most expensive have seen a 96.5% hike.
Season-ticket packages had been available, guaranteeing seats for each London game with a discount, but they were scrapped after the 2024 season.
“It felt like a kick to the head for a lot of loyal fans who’d supported the games for a long time and spent a lot of money,” said Cullen, a former season-ticket holder. “But I do understand the NFL wants to bring new fans in.”