The event PvE things are neat, a few times, doesn't seem worth it to spend money for just that. It'd make more sense to have the events be semi DLC, where you can only get specific DLC skins and weapon graphics. Golden weapons is boring. Most of the event skins are crap.
An updated Mercy DLC Witch skin and a DLC broomstick instead of the regular staff? That kind of stuff would be nice. Maybe even make the weapons/abilities have a small bonus modifier for non competitive play during the event, and a bigger bonus for the PvE crap. Animated sprays, that'd be cool too.