comic zin

As title asks, what is the best Paypal-accepting Japanese product proxy service you have used for buying JPN goods like manga, anime, and games? My definition of "best proxy" means final cost for the proxy's overall service fees are cheap, so like ZenMarket which charges only 300 yen service...

I have recently come across COMIC ZIN's online store, from what I can make out of it, is a doujin store. I've been wanting to purchase the delectable doujins from the store site but I can't find anywhere where I'm supposed to "Register" for a store account. Someone help please? Already looked up...