I am curious to know about the average development cost of Japanese RPG . Suikoden Tierkreis was released four weeks ago and it sold only 120K units . Was that enough to cover its development cost?

What's a JRPJ? Japanese Role-Playing Jam?

My guess would be somewhere between 2 to 6 million.

2-6mil kinda high and  if i remember correctly it cost roughly under 1mil to 3mil.  I dont really feel like digging up the development cost since i dun work on ds games but a friend mention thats was the usual. 6mil is one of the highly extreme big budget title compared to your 100m high budget game on the console.

but I'm unsure

 500k for low profile and 3 million for high profit? Makes sense.  Once again, those were guesses.

Imagine the profit which DQ 9 will make :O

On August Famitsu released information regarding Suikoden Tierkreis saying that is is 50% complete. It got released on December so I guess it is a low profile game .

DQ IX will probably have been more expensive than an avare DS JRPG, but indeed, SE will swim in money this year.