Ace Attorney is different, it's a text based game built on a small budget. 250K for that game is pretty goddamn awesome. That means they'll more than make back the budget. Which means, yes, the games are doing pretty well. Or were, since apparently AAI didn't sell enough to warrant AAI2 coming out here. Apollo Justice was the real start of AA's sales dropping off.

Breath of Fire selling 250K is a different story. For RPGs to do well, they have to do at least 500K in this economy or it'll be a flop. BoF1 was the only one that really did over 500K. I doubt it really sold a million, because it was an underdog compared to FF; any RPG that wasn't FF pretty got their asses kicked in sales back then. But another thing is, you linked to VGChartz, which in gaming circles is known as a laughingstock because their numbers for lesser-known games are never accurate. IIRC, Capcom themselves said that BoF sold 3 million units collectively. This is spread across 15, count 'em, FIFTEEN titles. That is 200 thousand exactly for each one.

Assuming BoF1 DID sell that much (I still doubt it), this means that it should be 2 million divided by 14, which is around 143K. Keep in mind this is 143K a game, assuming they sold evenly. This isn't that great by RPG standards, since RPGs have huge groups working on them, and they normally take longer to complete. Time=money. Before I forget, the 15 number counts the ports as well, which, if you think about it, drives the number even lower. Add to that that a few of these are cellphone games, and the numbers for the main series become even more dismal. Cellphone gaming, believe it or not, is a big market in Japan. That's why Squenix and Capcom and whoever else is latching onto it.

Ace Attorney doesn't compare because a bulk of the work goes to writing and planning the story. As you may have known already, the AA games reused a lot of resources from game to game. Even some of the later new characters were redrawn from older sprites. The Street Fighter and Mega Man series, among others, did the same thing. BoF was unique in that it didn't really reuse much in the way of sprites. Every BoF game has a wealth of new resources. But as time went on and the sales went down, the budget kind of overtook what they were making back. But at the same time, they were cutting corners by the time IV came out to offload the rising costs of development.

This is why when you play IV, Ryu and Fou-Lu's transformations are relegated to 3D cutscenes, and why they basically just look like overgrown bats on the battle screen, instead of dragons. There's no true world map, and the game is EXTREMELY linear and not very flashy at all like the previous ones. The desert motif gave Capcom an excuse to make the game kind of empty compared to the others. And I would also say that DQ took no huge effort for Capcom to make, honestly. I like the game but it smacks of a short development time. Apparently from what I've heard, the game started development in mid-2001, so that means it didn't even get 2 years of development. It originally came out in 2/2003. Add to that that MMX Command Mission had started development as well, so the BoF team was focusing on 2 games at once. Since MMX was more popular than BoF at the time, well, you can see what happened.

This sorta relates, but I got to the point where I beat DQ in one sitting about 2 years ago, and was shocked at how short it was. Think my final time was around 8 hours, 25 minutes. That is SHORT. That's even shorter than Parasite Eve. That's when I knew the series was dead.