Anyone out there ...

Know what the going rate for babysitting is these days? I put an ad on Kijiji for childcare, and I've received a couple emails in response, but when they ask about 'my rates' I'm not sure what to answer, as I don't want to sell myself short - this is to be a source of income over the summer - but I also don't want to aim too high and shock parents. I'm sure it's gone up from the $4/hour for the one child, plus 50 cents an hour per additional child I charged when I was a thirteen year old lol.