I really don't know it depends on what audience you want to catch.
I'll say you budget the size of your story what I mean is how much story you need for your idea to feel complete and then shop around for artist to see how much would it cost.
I'll say Bulk would be more advantageous since people have short attention spans so releasing stuff regularly would maintain their attention for longer time and give the opportunity for more people to become aware of your story.
The if enough people want to see more you can make a patreon or something for more quality stuff. But that is just me.
Have you read anything about online marketing? it would be advantageous to understand how to catch internet interest before coming up with a plan.