Thanks everyone.
teck, I wouldn't limit yourself to just yohji when it comes to the oversized silhouette. Yohji seems to have quite the cult following so Ebay prices are a bit inflated but I would look at Miyake and CDGH+ too. Although Kawakubo's current collections are much slimmer, Comme's pre 2005 collections tend to be cut much looser and they are also quite neglected on ebay. I've been looking at these awesome wool (not cupro as the seller says) pants for the last couple of months and it looks like someone has finally decided to bid on them and it's ending in a day.
Miyake tend to have more people willing to buy the older stuff but there are still great pieces that pop up without any bidders. And the good thing with miyake is that a lot of the 80's and 90's womans jackets are so oversized that they are practically unisex. This jacket has also lasted a few months and is at $70 now
Also look in the woman's section. There are quite a few mislabeled pieces for yohji, comme and miyake. I've seen a few main line woman's Comme pieces that have been labled as men's and have failed to sell for peanuts so I'm sure it's the same with men's stuff in the woman's section. But if you are set with yohji, dont worry about sizing too much. The pants I got are a size 4 which are 2 sizes too big for me. But any of the drawstring trousers can be drawn in and while I may have my pants shortened, rolling them up (or im using the drawstrings at leg openings to shorten my pants) is also fine.