Do these third versions stilll sell? Haven't Pokemon fans figured this scam out yet? Maybe there's a large chunk of people who intentionally wait for the third version and don't buy the original and another chunk that only buy the original. But the two groups are large enough that it appears that people are buying both.
Nah, I'm giving people too much credit there.
The rules of gaming are simple. Never buy a Pokemon or Metal Gear Solid game on day one because a better version will ALWAYS come out within a year.