First of all, you will find a lot of brands cheaper on Ebay, or old collections that have sold out in stores.
By just typing in the brand name, selection the world wide option, and classifying the list on 'item+shipping lowest price first' you will be able to find really cheap auctions.
Auctions are the best way to find brands on a budget.
For example the military collection from Lip Service Division collection from fall 2008.
These shirts are not for sale anymore at lipservice themselves, but I managed to find one of the shirts on Ebay.
Now for non brands. You can find AMAZING things on Ebay. I love punk and cyber looking clothes. Japanese and Chinese brands offer great unique items at cheap prices. Let me show you.
This awesome dress is available in 3 colours, and from size S to L, note that they might size smaller than what you are used to. So leasure yourself (or let someone else do it) to make sure everything will fit! Most items will come with a size chart with measurments. If the chart isn't included, you can always sent the seller a message for it. The dress is a steal for only 20.98€! (No shipping, buy will take about a month to get to you)
You can also find auctions for brand items such as Punk rave, these start really cheap, and often sizes are put on auction seperatly, so you have more chances to find your item cheaper!
If you want a brand item, alsway search how much they are sold in non auction, so you don't overbid on it!
The official webstore of Dane doesn't exist anymore, but they are on Ebay, if you want one of their items, they can all be found here. You can also sent them a message for special made items.