The Ico/Shadow collection also had one less game that had to be ported. The developers also didn't have to spend time and money bringing that collection to two different systems. They could focus solely on the strengths of the PS3. In a way the extras helped to justify the $40 price tag to consumers when other companies were offering 3-game collections for the same price. Plus Sony didn't have to worry about paying any hardware royalties to publish the game. That allowed them a larger profit margin on each disc sold compared to the DMC collection and therefore they could justify investing more the collection's development.
I'm sorry, but there is no reason Capcom couldn't have done a proper job on this and still maintained the $40 price tag. There are literally companies now that specialize in these HD remakes and they essentially do the work for a few hundred thousand dollars using a small team. Hardware royalties and replication fees are very minimal and other companies seem to deal with them just fine on their HD collections. Capcom just did what they have been doing more and more lately which is delivering the bare minimum to squeeze out the maximum profit.