Japanese used trains market

[Need for High Speed]

I finished setting up a papal account and what not and I set up a Buyee account a few weeks ago, so I am ready to buy the Tenshodo JR500 now.

But the Yahoo! actions market for HO bullet trains seemed to be very busy over the past few months their was a few in January and nothing much in February and March but then in  April things seemed to pick up. When I finally set up a Buyee account towards the end of June things seemed to hit a rock wall, I know its not been that long but for those who have been observing the second hand HO market in Japan for a longer time do you know if their are any patterns to follow or is it more random and just got to keep checking every day and see what comes up? I have only been observing for about 8 months. The second hand ebay markets for American and European trains usually have more stuff in October through December and the spring. I am wondering what it is like for Japan?