I don't sell eliquid, but I have embarked on a couple of sell-from-home ideas that taught me how easy it was to lose money. With all due respect, I have no personally-proven advice to give anyone on how to "recoup costs pretty quickly". I do have some knowledge of just how difficult it is to do, though. Think of the time to fill and label those little bottles. You can't just look at material costs without looking at time spent/labor cost.
I did think about it, and those samples would be a loss leader. Expect to make nothing to very little on something like that, but it's the repeat business that will draw the customers back, and that's where you make the money. Alice in Vapeland is a good example. Full slection of samples, little charms on the bottles, real glass, etc. They get so much business that they can only stay open for a couple of hours, once per week. Customers will probably buy the samples only once, or maybe several other times to give to friends.
One of my buddies owned a McDonald's franchise and he told me that McChicken's and McDouble's cost more to make than what they sell them for, but they make it back and then some by selling french fries, sodas and other things along with them. The same principle applies here.