Where so you get this from?
There is a mandated minimum that is around the median salary of my country, so much higher than minimum wage of most countries.
New young riders in the UCI Pro Tour level reportedly get a fair bit more than the minimum, on the Tour they are not usually fielding a more experienced team and earn more. If they prove themselves the earnings go up fast.
Cycling pays little compared to basketball, football etc. but they are well paid compared to the general population at Tour level.