i am a new mixer and I haven't been able to find pure unflavored nicotine... i had to purchase 120mg of already mixed vg and pg with nicotine level 6....that is not cost friendly
Whatever you get, try to keep it in the freezer. I prefer it in PG (thinner than VG and easier to pour)
This is where I buy mine. 100mg vg base by the liter.The strongest you'll want to handle without being in a lab is 100mg in a base of either pg, vg, or mixed. It isn't safe to handle "pure" nicotine without special equipment or unless you're a chemist or someone who is trained in the handling of hazardous chemicals.
First place I'd check would be www.niclabs.com. That is the site that sells what used to be Delosi nicotine base.