The wages vary a lot, as has been said. At the top end it's into 7 figures for a select few, and generally div. 1 riders are well looked after. Though compared with very average premier footy players, they earn in a week what the average domestique might need up to a year to make. Go doen the levels (compare div 2 - pro-conti) with championship footy and the proportions are not much different from the top, just lower maney. Getting below that there are some conti (div 3) teams that pay OK, some who pay a pittance, and under that at domestic level, most riders are a la musette (expenses and equipment only) any money coming from winnings, so that's a very hard life. Toughens them up if they make higher grades, though.
Compare that with footy again, even non-league teams pay players and managers quite well, although a few are part timers, like most domestic team riders.
Moral, if you are not a top star, cycling can give you a decent enough living for a while, but you won't make your fortune and when it's all done there had better be some other way to make money.