Costs:
Pay - watch out - nannies quote pay per hour NET, you have to pay GROSS + employers NI. www.nannytax.co.uk has a table to convert net wage per week to gross wage per week. If the nanny has no other work, then the whole of her personal tax limit applies, and there is less tax to pay. Round here nannies were asking for £5 to £7 per hour NET. We couldn't quite afford the top end nannies, BUT if they were in nursery, they'd largely be looked after by the more junior staff anyway. Our nanny may not be completely perfect, but I am SO pleased we have her - she's great - really attentive, unflappable, full of good ideas. And DS1 was getting really poor continuity in his nursery we never knew who was supposed to be looking after him.
Hidden costs - I was comparing having a nanny with me staying at home, so the extra costs were:
agency fee (we didn't pay one, but could have been approx £400)
car insurance (depends on car and age of nanny - we allowed £250/yr - we insure nanny on our car as I don't use it to go to work - if using her own, allow 40p/mile, plus you provide the car seats)
nannies lunches (food at home or out for nanny - ours brings a packed lunch, but we allowed an extra £5pw for a 3 day week which is a bit OTT) also at the moment your kids food is included in their nursery bill, but if at home will come out of your shopping bill)
extra activities (nanny typically does a little more than I would in a typical week - allowed extra £5pw. Obv compared to nursery where there are NO extra activities, you could be paying out more to take them swimming / soft play / farm park or whatever - but clearly the kids benefit from going to whatever)
nanny use of phone - I give mine a £5per month allowance for use of her mobile while working for us
Christmas bonus / presents / b/d presents etc - I allowed £150per yr
approved childcarer fee £96 per yr - we pay this, but as we get the tax-free vouchers it saves us £2000per year
NannyTax to do payroll £150 per yr (get rebate as they file on line)
plus I added in my costs of getting to work / work clothes etc as I was comparing with not working at all.
I allowed for £1400 to £2000 extra hidden costs, but in fact it's probably nearer £1000 - car ins being the biggest (I have a big car).
Hope that helps.
TBH, my job can be quite demanding, I have some extra personal stresses, and DH is rarely here to help in the am. There is NO WAY I could be getting the two of them ready and to nursery in time to get myself to work. I couldn't cope, and take my hat of to those who do.
An additional advantage is if your local preschool is a feeder for primary school then your elder is getting to know his school friends, and also if you want to use extra sessions there for the days yr not working, it's the same place for him IYSWIM. IME, sessional preschools have a nicer atmosphere and do the 'early yrs education' thing better than daycare, but that may not be usiverally the case.
ALL nannies I interviewed had worked in nurseries and said they prefered nannying as the
children got more attention.
This is my own exp, and I know people are happy using nurseries.