Freudian, I think lots of people will have sympathy with your POV, so don't feel victimised.
My problem is that lots of women seem to think that because they were once married to someone/got impregnated by someone, they can expect to be helped out by that someone for ever. Yes, NRP should pay the correct amount of maintenance. no question.
But, in my opinion, RP shouldn't expect their ex to go without so that they don't have to. ie, in given situation OP doesn't want to go without (a takeaway, bottle of perfume, evening out, take your pick) in order to pay for DC's bed. NRP already pays maintenance, so why should he go without (a takeaway, bottle of aftershave, few beers, take your pick) so that she doesn't have to?
Has OP really been to Las Vegas? Hard to claim she needs the money.
NRP should pay the correct maintenance and RP should leave him to get on with his own life and not expect to be supported for the rest of hers. Sorry OP - sounds harsh, but directed at all those who fail to realise that an ex is just that - an ex. He should support his child, but owes his ex nothing.
Unless OP is planning, as someone else suggested, to give NRP half towards DC's bed at his house. In which case, why bother?