DMC3 Lady and Gloria costumes count as DLC and there's no way those costumes are going to be free later on. It'll be like $4-6 for them.
Broadly speaking, paid day 1 DLC is fine as long as its purely cosmetic and peripheral, and it's not on the disc. Gameplay content DLC later down the road is fine as well as long as it is quality content, doesn't feel like it's a piece of the main game that was cut, but instead complements the main game, and that it's fairly priced. I'd be okay with something like a DLC campaign for the secondary characters in DMC5 as long as it followed the previous criteria.
Broadly speaking, paid day 1 DLC is fine as long as its purely cosmetic and peripheral, and it's not on the disc. Gameplay content DLC later down the road is fine as well as long as it is quality content, doesn't feel like it's a piece of the main game that was cut, but instead complements the main game, and that it's fairly priced. I'd be okay with something like a DLC campaign for the secondary characters in DMC5 as long as it followed the previous criteria.