Just ran across this page (
http://vgstats.blogspot.com/2011/08/famicom-price-guide.html ) which catalogs all the Famicom game sales on ebay for one year. Here's a quote from the original page explaining how they got their data:
Methodology
Includes all Ebay listings with the word "Famicom" in the title from August 23, 2010 through August 22, 2011. Only includes single loose carts (no lots, or any with a box/manual). A total of 4,356 games were sold over the 365 days, for an average of 11.93 per day.
Only sales from the American Ebay site were included, in American dollars only. However, this does include many carts sold from Japan (easily the majority, I'd say).
Only official licensed releases were included - no pirates. No Famicom disk system games either (sorry, I wasn't interested in them - besides, they're much less likely to be found loose).
Only games with at least 3 sales are included below in the guide. So that ends up being 392 titles.
All prices below are for the total price, including shipping. I live in Illinois, near the middle of the country, so it should work out to be pretty fair. The average price was $13.77 shipped for all games (median = $11.05).
I did a quick browse-through and saw that the KNT Famicom game averaged a going rate of US$27, including shipping as explained in the above quote, for an officially released (non-pirated), cartridge-only sale. That seems fairly accurate, but I wish it were a bit lower--I'd love to get a complete copy (box+manual) for a decent price, but if cart-only costs nearly $30 I shudder to think what the going rate is for a complete one. Maybe the ones I have seen in the past, which I thought were way overpriced, were reasonable after all...
Anyway just something I thought was interesting and might be of use to someone on this forum.
From the source page:
PRICE JAPANESE NAME AMERICAN NAME
(. . .)
27 Kyattou Ninden Teyandee -----