bevelino
Ouch!
If you are inferring Oxbridge for you DD then there are a number of plus sides. College accommodation tends to be cheaper, although there are variations between colleges, and is for most available for all three years. DS1's college is fully catered, but only charge for meals actually taken. Best of both worlds. Compare with somewhere like Durham, his insurance, where catered now starts at around £7k per annum with all meals included whether eaten or not. Conservatively, for him at least, Cambridge is a good £2k less per year to be at than Durham
Add to that the sports clubs he is part of have no fees, the annual gym memberships is only around £20, there are a plethora of non income dependent travel bursaries etc.
And whilst it is true that property prices in both Oxford and Cambridge are high, very few undergrads are aiming to get on the property market as soon as they arrive!. A pint of milk, load of bread, packet of pasta costs no more in Cambridge than in Cardiff or Carlisle.
DS1 got a very good job, more of a placement, straight after finishing A levels. That paid very well and more importantly has opened more doors since then. I'd recommend any DC thinks carefully about what job / experience will really enhance their CV, differentiate them from the crowd, and provide future opportunities. A gap year is worth considering. More so if all 3 or 4 are going to be at Unis (I guess potentially 3-4 different, geographically scattered Unis as well) at the same time.
Of course maintenance loans are dependent on household income, and you've probably seen the student loan calculator and have a pretty good idea about what your DCs would be entitled to. From that you could look at some best, middle, worst case scenario's and assess what is / is not financially feasible. Dependent DCs are taken into account when Student Loans calculate household income, although with my other DCs still being at school (and hopefully I'll have no Uni overlap with them all) I dont know if or how twins / triplets etc also at Uni are factored in. Could be worth giving them a ring to find out that too. The dependent income reduction is not huge, but all counts.