Not sure where you live, but we pay $120 per day for daycare in Sydney.
It's easier not to pay for 2 in daycare at the same time, if you leave enough time between them one can be starting free state school whilst the other starts day care. Most people seem to plan it so there's only about 2.5yrs between them, however.
You just stop spending money on yourself, you don't really have time for this anyway (no longer time for weekend hobbies, evening classes, mini breaks, shopping sprees etc).
'If you can't feed 'em, don't breed 'em!' (Said someone).