Please help - finding a teenage prom Dress

My goddaughter who has asked me to help her find a prom dress is keen to find something “not too expensive”. Any suggestions would be gratefully received. Thank you

asos design and asos luxe are worth a look. But I would also recommend taking a look at rental sites. They have some gorgeous dresses on there which you can rent for a fraction of the price. Also worth having a look at these brands