I found the following: but it is from the old format I believe. The same article says I think it's the Australian version you get about £75 a day
Former contestant Clark Sherwood, who appeared on the 2019 UK version of the show, previously explained to Cosmopolitan that while the participants are given money to cover some of the wedding costs, they must pay for certain extras themselves.
He said: “There’s no financial gain from going on the show. There’s a budget for things - her wedding dress, a small budget for the suits. There’s some money for the hen-do and stag-dos, but it was mainly out of my pocket.
“I think they put money towards travel or something. But there was genuinely no monetary gain. Lots of people think, ‘No one would do that for free,’ but actually I spent quite a lot of money on the process.”