So I was looking through the videogamespricecharts website, checking out prices/trends for a few games....and something caught my attention. Below are the sale averages for all the Mega Man's on the NES. Yes, yes...we all know the numbers are rough figures...but they still provide some useful info that I don't get...

Mega Man $25.74
Mega Man 2 $13.84
Mega Man 3 $8.79
Mega Man 4 $12.68
Mega Man 5 $32.49
Mega Man 6 $26.74

But I can't make sense of this data. The way I rationalized it in my head is as follows:

Mega Man - The first one released. They didn't know it would be a hit, so the production was limited, hence high value.
Mega Man 2 - After success of 1, the production was obviously increased, & with greater supply...comes lower value.
Mega Man 3 - Same as 2. Production was increased even more...which is why this one has the lowest value.
Mega Man 4 - Value still relatively low. Maybe production didn't equal #3, but still great enough to cause low value.
Mega Man 5 - Here is where they lose me. In terms of value, this is the costliest Mega Man to obtain. Why did they produce so few copies? What changed after 4? I don't get this one.
Mega Man 6 - Also fairly costly. Again...I can't make sense of it. Why such low production?

What am I missing here fellas? I don't understand the logic behind some of the production numbers.

thank you.