But homemade oil distillers like, I think my godmother has one-- she pulls oil from herbs for hoodoo work with it, looks like some kind arcane alchemist's equipment-- not sure if that'd be a cheaper method or not, though.

EDIT: https://www.sciplus.com/p/ESSENTIAL-OIL-DISTILLIATION-UNIT_53893

Something like this, maybe-- if you were willing to lay hands on the herb yourself. Not sure if it'd be cheaper, might shoulder added risk, but I could be wrong. Then again, I love DIY shit like this.

It's an easy process and it stays stable.

Also if you try the vegetable glycerin route find a source that hasn't stored it in plastic containers anywhere in the supply chain. The end product will taste like plastic.

If you can only get flower look up the RSO process. The trick is to have it thin enough in room temperature to wick properly.

Good luck!

Using a rice cooker and everclear 190 proof.

Decarboxolate the weed (put in a 250 degree over for ten minutes) then grind it up, but don't grind it into powder.

Put the weed in a clean five gallon bucket and pour everclear til the weed is covered. Mash it with a clean piece of wood for about 5 minutes. The shorter the mashing period, the more potent the oil. Under three minutes makes very strong oil. You can go up to ten minutes, and you will get more oil, but it will have some water solubles in it at that point.

After mashing, pour through cheese cloth into a container. Then pour it through a paper coffee filter into the rice cooker. Boil it in the rice cooker until the alcohol evaporates away. When it is the consistency of thin gravy, it is done.

Here we draw it up into oral syringes for easy dosing.