Some people think ethical or eco fashion is expensive (though if you choose something that lasts longer it may end up being cheaper in the long run!) but being a responsible consumer doesn't need to be more expensive, nor should it be less fun.
One great way of updating your wardrobe without costing you much is to throw a clothing swap party, where everyone brings items that they don't want, exchanging them with each other for free. These parties are also a fun way of meeting new people, and therefore a much richer way of "shopping".
There are different ways to do the exchange part, but the ones I've been to usually started with having everything in a big pile in the middle and having everyone say a thing or two (e.g. something interesting about one of the items they brought), and then trying things on, recommending things to others, etc. I've found a lot of things through these exchange parties that I would otherwise not have even thought of trying on.