I have found good deals on plus-sized clothing in the outlet/sale sections of the online stores of Talbots, Coldwater Creek, Ann Taylor, and TravelSmith. You might find similar deals at their brick & mortar stores, and you can find your size at their stores before ordering online. I also like Lands End online where their sale section is called Overstocks. If you need to return anything you can do so at any Sears store to save postage. Sears bought Lands End a few years ago, and Sears has tried to maintain the better quality of Lands End clothing that was synonymous with the LE brand .
Aanother possibility is to shop for brands you know on ebay. Just specify in your search NWT, which means new with tags. You can often get good deals that way. Again, know your brands & your size in those brands. As always look for sellers with high reputations. I don’t buy from anyone with less than 99.8% reputation & try to find those with 100% reputation and lots of sales.
Click title for link at MoneyCrashers for totally different ways to save on plus-size clothing. I haven’t tried the methods suggested.