My daughter and I enjoy switching out flavors frequently. The biggest bottle we usually order is 30 ml.
When trying a new vendor, or a new flavor from a trusted vendor, I like to order the smallest size available. If we like the flavor, then we consider what size to get when we reorder. Since my daughter vapes at 18 mg nicotine, and I have gone to 12 mg nicotine, it does not make much sense to us to order huge bottles. Neither of us is a "just one flavor" type of person, although we pretty much have to have Mt. Baker's Hawk Sauce on hand for my daughter - it has been her "go to" vape for stress relief since the first time she asked me to order it. (We share housing and living expenses, and the vape budget usually comes out of my disposable income.) I never would have ordered this for her, since it does not fit her usual flavor profile. Once I told her that I was tired of ordering eliquid for her "blind", trying to guess what she might like, she checked out the site. She had me order the Hawk Sauce because she liked the name. After a few "meh" puffs, she discovered she actually really liked the flavor, and it is one of the few eliquids that we make sure to have on hand.
I tend to favor bakery/custard/creamy eliquids. If you absolutely have to order a large bottle from Mt. Baker, I would definitely recommend the Cinnamon Roll. It is one of my favorites from them.
If it were me, I would order several flavors in smaller sizes, after looking at the flavor profiles and reviews on the site. I do like it that Mt. Baker shows all reviews of their flavors, both good and bad. You will be in a much better position to order a large bottle once you have actually tried a few flavors, rather than potentially wasting the money on a large bottle that you may or may not like.