"...semi-final ticket prices have crashed as previously optimistic Irish, Welsh and Scottish fans seek to offload their tickets, now that their hopes of making it to the next stage have been shattered," the spokesperson said.
Category A seats to New Zealand versus South Africa - with a face value of £515 (NZ$1206) each - are currently going for NZ$771 each. Before the weekend, a category A ticket to this game was NZ$1068 on the site.
Category B tickets are also going for less. With a face value of £315 (NZ$737), the tickets were selling for NZ$741 on Friday. They are now NZ$568.
Category C tickets, with a face value of £215 (NZ$503), were going for $680 last Friday, but are now $458.
Although category D tickets are still going for over face value, they are cheaper than last week.
A category D seat has a face value of £125 (NZ$292), but is going for NZ$440 on Viagogo. This is NZ$103 cheaper than they were last Friday.
All category tickets for the Australia versus Argentina semi-final are being sold for less than face value and across the board are cheaper than Friday.
It seems the demand is there too.
In the 24 hours following the weekend's games, the site attracted more than 50,000 searches by New Zealanders - five times the number of searches between Monday and Saturday last week by Kiwi fans.
Meanwhile, here in New Zealand, more people watched the All Blacks quarter-final against France on TV on Sunday morning than any other game so far this World Cup.
Figures sourced from Nielsen TV Audience Measurement (TAM) AP5+, based on a national audience of 4,200,880, show there were more than one million people watching the game.
This is live coverage on both SKY Sport 1 (637,000+) and Prime (416,000+) - equating to 15.2 per cent of all people aged five years and older in New Zealand watching the game live on SKY, and 9.9 per cent on free-to-air Prime.
Power company Vector also reported a peak in electricity demand on Sunday morning, spiking at 8am and again during half-time.