I do not go out on a cold, dark and generally in this country rainy night, to sit in someone elses house for a few hours for less than £9 per hour (depending on the family, I babysit for some less well off families for less or for a spot of bartering!) I generally get £11 per hour and £12:50 after midnight. I have 23 years experience as a sole charge nanny, I have a current CRB and pediatric first aid.
I have babysat for a family whose 4 year old was sick in her sleep and was choking on her own vomit. A family whose 8 month old had febrile convulsions at 11pm (he'd never had one before. A family whose 2 year fell out of bed and broke his wrist. A family whose 7 year old pushed his 2 year old sister down the stairs because she had woken him up when she woke up having a bad dream (never seen such a big egg on a forehead!)
I have also babysat for families where the kids are little buggers and won't do a bloody thing I ask them and so I have 4 hours of running up and down stairs trying to get them settled or families with babies who are teething/have wind/are suddenly unwell and they are not "cushy" jobs!
Tonight I am babysitting (for £12 per hour) for 7 year old twins from 6pm who wont got to bed until 8 and will be up and down the stairs on various pre-texts until at least 9:30 (I don't actually mind as they are ex-charges and I don't get to see them that much!)
Now, I know that these things don't happen very often and are unlikey, but do you think your teenaged babysitter/cleaning lady/old lady from down the street would be able to deal with any of these problems? If you do fine, pay them what they and you think they are worth, if not, stay home until they are old enough to look after themselves!