This is a very interesting thread. The situation is reversed for me as I am the resident parent and recieve regular payments of maintenance as set out by the CSA from my exH. He will not contribute towards anything else.
However, I do think every individual case is different. DH and myself have found it a real struggle at times to be able to afford all the extras for the DC (I have 2 with my ex and 1 with DH). ExH and his wife are considerably better off than DH and I, which I certainly do not begrudge them for, it's just at times when DC's 1&2 for example have school trips we have really struggled to scrape the money together and exH won't pay a penny towards it, it's times like this when I feel like it's not fair.
When exH and his wife had their DD, I had to take a cut in the amount of maintenance he paid for our DC's which knowing their circumstances certainly was not fair to our DC's as they were the ones affected.
At the moment I am faced with exH moving away as his wife has a new, very highly paid job which comes with a lot of perks. A fantastic opportunity for them but unfortunately for my DC 1&2 not only will they not be able to see their DF on a regular basis he is giving up his job to be a house husband and look after his other DD (they have another on the way also) so he then won't be legally entitled to pay maintenance which will mean I am going to have to say no when it comes to school trips and extra curricular activities that cost money as DH and I just will not be able to afford it.
As I said before it does depend on the individuals circumstances. I have only ever asked my ex twice for money other than the maintenance. The first time was when I was a single parent and I asked him for some money towards a sheep costume I was making for DS's nativity at pre-school, he said no. Years later I asked him to pay half of DD's extra curricular activity as DH's hours had been cut in half and we really couldn't afford to pay it all (was the start of the credit crunch), at first he said yes then after I'd paid it myself never gave me his half of the money. My mother ended up giving it to me instead.
On the other end of the scale I agree that there definitely are women who just ask for way too much. My brother pays his ex maintenance, buys his 2 DC's their uniform, shoes etc, pays for their clothes and school trips etc. Pays for them to go on holiday with their mother and she once even asked him to give her spending money, think he drew the line at that!!
Bebo good luck for the future 