You can get those Chop Seals for about 50-100rmb each depending on where you shop. Its been years since I was living in BJ but back then they had an antique market and the silk market.. if they are gone post the olympics then no worries, I am sure they've been replaced.
If you get 5-8 seals done at the same time you can negotiate heavily on price point, they normally come with a small box and pot of red ink.
If you have some skillz with Chinese, hit taobao.com - search under boardgames or 桌面游戏. Lots of bargins there. Its not asian themed (and you'll need to be careful what you are ordering is the english version and the components are english) but they have great stuff.
Finally, individual paper/silk fans are pretty cool too - they can pull them out for the JR sessions and/or use for groovy halloween accessories.
On a side note - Printing costs are insanely low in China. I had a Print Your Own version of old Dune game done (see boardgamegeek.com) and am very happy. If you want to make asian themed player folders, packets etc for character sheets and so on, you can do it for cheaper than kinko's.
