Should new features in a sequals cost extra via DLC?

since some posters here thinks it acceptable that Capcom is charging exta for their versus mode for Resident Evil but what if this trend catch on with other game makers.

what if bungie charged extra for forge mode, infection game type and theatre mode? since all those is new to halo series.

what is activision charged extra for their nazi modes? since thats new to CoD series

I will only pay for content that the developer worked on after release in order to provide longevity to a game, such as new maps, play types etc. If they just cut it out, then i'm not going to pay for it.

As long as people will by it, then it's something that will catch on, so let's hope nobody is that stupid.

May I play Devil's advocate here and suggest that Capcom is possibly charging extra for multiplayer because their budget was exceded by the development of the multiplayer mode. I mean it's always possible that they're just ripping us off hardcore, but if I were to hazard a guess other than pure boneheaded consumer exploitation it would certainly be that.