Discount children's designer clothes?

Hi,

My partner has a 4 year old daughter with his ex. His ex only allows their daughter to wear expensive or designer clothes ie clothes from House of Frasier, Baby Gap, Pumpkin Patch, DNKY, etc.

My partner and I can't afford and don't believe in paying £50 for a t-shirt for a child that is going to grow out of it in a few months - of course we want her to have nice comfortable clothes but we don't believe that that means paying £50-100 for a designer t-shirt or trousers.

We have bought loads of clothes for her from H&M, Next, Debenhams, Mothercare etc but she never wears them and we just found out that as soon as the mother saw the label she just binned them.

My partner has just finished uni and is having trouble fining a job with his degree and can only get work for 6 week periods and then nothing for weeks so he doesn't have a steady income coming in. Even with this he still pays her maintenance directly to her even though the CSA told him he doesn’t have to pay maintenance and refuses to take money from him. When he does get money in he always buys her something, nothing big but something small like some new outdoor toys, or a game etc but nothing extravagant but this is not good enough - the mother expects something around £100 spent on her nearly every week.

I have a full time job at the minute but am being made redundant at the of July and going back to finish my degree in September, but after I pay rent for myself and my partner and household bills I only have £200 left to live for the rest of the month so I can't afford to give my partner a lot of money to spend on designer clothes.

We have tried to explain that she doesnt need to be in designer clothes all of the time (especially as she is not allowed to get them dirty as they just get binned straight away - not washed just binned as she decides that they are no good anymore) and that we can't afford to dress her in them but that clothes from Next, H&M, etc are just as good.

Does anyone know of any websites that sell designer clothes but at a discount price?

Thanks for any help!