Hands-down the best place to buy parts is Rdvtg-hobbies on eBay. They sell out of Japan for prices lower than anybody else. Plus their shipping is only $2 for the first item and $1 each additional item. They even arrive at my door in under a week.
Here are the two slippers for way cheaper than what you posted:
http://stores.ebay.com/Rdvtg-Hobbies...w=db01+slipper