Reddit mentions of 1 Gallon of Vegetable Glycerin USP Food Grade 99.7+% Pure Derived from Pal Fruit

Pretty much. If you've ever looked at them closely, this is what it looks like broken down, which is a lot more than you need to do here but it'll at least help you see the anatomy of it. What you'd do is:

• get the chimney off (the top metal part with the rubber gasket)
  
• pull the wick (the two little loose white threads and the one big one that's threaded through the wire coil) out sideways with tweezers
  
• twist/roll some wicking material (hard to describe exactly how much you should use but you should be able to figure it out with a little trial and error, it's not like you'll have a shortage of cotton/rayon) tightly enough to thread through the coil
  
• thread some through the coil and lay a little more on top, untwisting/unrolling it just a little to expand it
  
• replace the chimney, grab some scissors & trim the coil flush with the widest edge
  
• place coil in tank as normal
  
  That's pretty much it but like I said before I highly recommend rayon wicks for flavor, so much so that I was dead serious when I offered to send you a baggie full for free, it's really that good and if it'll help you kick analogs once and for all it's more than worth it even if you don't pay it forward eventually (though I would ask you do that if/when you're able, the little baggie will last you at least a few months but the $15 box my wife and I have will last us several years even if we give away 3/4 of it).
  
  Also, if you really want to save a lot of money (and possibly get a new hobby lol), look in to making your own ejuice. It's only as difficult as you want it to be, it can be as simple as mixing two ingredients in a bottle^(1), or you can scale up the complexity as much as you like^(2).
  
  Hope this helps!
  
  ^^^^^^^^^.
  ^([1] One quick example, say you really like )^(MBV's Banana Cream Pie)^( and want to keep your nicotine around 9mg/mL, just mix 24mL of )^(12mg base)^( with 6mL of )^(BCP flavor)^( and that's it!
  [2] cheapest way to go is getting )^(100mg/mL nicotine base)^( and get )^(straight VG)^( and )^(PG)^( to dilute it to your desired strength; plenty of recipes on /r/DIY_eJuice to get you started mixing your own concoctions, some with only one or two flavor ingredients some with more than six!)