Am I being unreasonable

In summary, an outline of the situation:

Marriage: 7 years. Ages: Wife 32, Husband 42. 2 kids, ages 5 and 1. Total house and liquid assets 800k, in addition there are pension assets 200k (current equivalent value). Annual income including bonus 290k (say 14.5k per month). Current offer to wife: She keeps house with 450k Equity in it (house has 310k mortgage on it). She also keeps 50k of cash assets. Total to her 500k. I keep 300k. I'll use 40k of that to reduce the mortgage but I would want to keep the 5% of the house value assigned to me which she can pay to me when the kids leave school. The rest of the cash left to me I'll use to buy a 2 bed flat nearby so I can be close to the kids (need huge mortgage for that). I will also give her 50k of the pension pot.

With regards to income, she has historically spent £3k per month (excluding mortgage) on herself (clothes, going out gym etc), running the house (all bills, food etc) and the kids (clothes, food, entertainment etc.). I'm proposing to give her 5k a month to cover the mortgage (post reduction of mortgage the monthly payments will be about 1.3k). In summary, post mortgage costs (and with child benefit) she'll have close to £4k a month to live on (whereas she used to spend £3k). I think this is a very reasonable offer.

Her camp say this is far too little and want maintenance of 7.5k per month, indefinitely. As this is over £2k per month more than she has ever spent in practice, I think this is totall unreasonable. I would sincerely like some impartial advice. Tell the truth, I won't be offended. If I am being unreasonable please tell me.....

Many thanks guys.

CSA would say 20% of net income for child maintenance, thats £3k per month to start with.
Then there's spousal maintenance which I know nothing about but ther calculator on this site will help.
How big is the house? If its got more bedrooms than she needs a court may decide it needs to be sold

Thanks chum. I would hope that common sense would prevail and we would look at total needs over wants, i.e. how much does she need in total (child plus herself). She'll never spend £3k a month on the kids so surely when setting spousal maintenance the courts would take this into account?

I would have thought so, but no expert

The asset split of roughly 60/40 is ok as kids involved.

20% of £290k gives £58k for kids.

Then a mortgage of £310k at say 7% repayment basis including capital and interest is £21.7k pa

Therefore courts could her to get a job to help pay say £6k of the mortgage therefore you need to contribute £15.7k

Therefore total is £73.7k or £6,100 a month you should be paying till youngest child is 18 then she can down size house and realise equity on property.

You could have a charge on the property for 28%.

Many thanks for that. Just to be clear, net income (after tax) is circa 180k (about 15k per month or thereabouts). 20% of that would be for the kids (36k or 3k per month). I would then need to provide spousal maintenance on top, which I am proposing is another 2k or so to bring it up to 5.3k per month (which includes her child benefit). This in my mind is more than adequate compared to actual expenditure. Note the mortgage will be reduced as I am planning to pay off about 40-50k of it, so the mortgage payments will be down to about 1.4k per month. Is that reasonable?

When you say I could have a charge on the property for 28%, where does that figure come from? Really appreciate your help. Cheers.

Max weekly wage reguarding CSA is £2,000 so earnings of 2k + per week pay the same amount which woudl be 20% = £400 p/w