I've been mixing my own for about two months now. I ordered a gallon of each PG and VG from Amazon.com, Dr. Adorable Inc, VG for 10 lbs, which is around a gallon, for $19.99 (though I think that was a special and it is normally $29.99) And I got the PG I want to say it was $39 for a full gallon. I've barely made a dent in my VG and the PG is about 1/3 of the gallon gone, since I tend to do a 60 or 70% PG to a 40 or 30% VG. I also have been brewing my own tea flavor using the PG, there's a little waste with that, but I do a half a cup at a time because it only has a shelf life of about two weeks before it goes green and tastes funny. Also wasted a couple of cups on bad brews, but that's the nature of trial and error.
For Nicotine, I've tried a couple different brands, I ordered a 30 mil 60mg nic from ecigexpress for my first try. Between me and my boyfriend we finished off that 30mil bottle in three weeks, it seemed to be accurate for nic levels. But I am completely sold on using Myfreedomsmokes. It's 100 mg nicotine, I got the 120 mil bottle and in almost a month we've used less than a 1/3 of the bottle. I kept my 60mg nic bottle from ecig and sharpie marked 100 mg on it and refill it with a syringe from the large bottle. It's much easier to work with if it's in a drip top bottle. I only use gloves when I am filling the nicotine bottle from the big bottle. Though if you are prone to getting stuff on you I'd recommend using gloves whenever working with the high levels of nicotine. I did at first, but I never get it on myself from the drip bottle, so I don't bother anymore. I mix all my bottles of juice to either 18mg for me, or 22mgs for my boyfriend (he likes it a little stronger.) I haven't had a single problem.
For flavors, let's see, Flavor Art is good, LorAnn is good, and I absolutely love The Flavor Apprentice. I wasn't that impressed with Cappellas, though taste is subjective, they just seemed really weak compared to the other three. I go through ecigexpress for the Flavor Art and LorAnn, though LorAnn also does have a site of their own, and it is a tad cheaper than the secondary venders are. I go directly through The Flavor Apprentice, because that is the cheapest way to get the flavors. Most are only $1.40 for 4ml. The higher concentration of TFA and Flavor art make your dollars stretch. I can mix many more bottles out of those two brands than I can any of the other's I've tried.
I start with 4ml bottles of flavors, I don't ever get larger ones until I know I like it. Like the Honey or Tobacco flavors from TFA...the honey flavor has to be diluted so much before it can be used, three drops in a 5ml bottle of distilled water makes it useable as a subtle flavor, otherwise it overpowers everything, clogs cartos, and burns out attys.
I also like the Sweetener, sour, and koolade (gives you a cold hit) from TFA. I just put an order in for 30 new flavors, I'm goint to give the Kiwi and a few of the newest flavors a go this week. I've been vaping a mix I called Pomegranate on Ice. With the koolade in it it tastes just like a cold pomegranate drink, add a little alcohol flavor, like rum, and it tastes like a mixed drink, though I can't vape that for very long. Chocolate Wintergreen Menthol is also a flavor I could vape non stop for days without switching. The double chocolate (clear) version from TFA is probably the best I've had so far, though I am trying the dark one this week.
In conclusion, to get the best prices on product you have to spend a good several hours searching through sites and for sites. I've got more links than I can count in my favorites, I had to put it in a folder of it's own to keep them organized. And I always stay on the look out for other places that might have things that are used for vaping, like the PG and VG, as long as it is food grade product it is okay to use for vaping. You just have to be certain it is. I also try to avoid any of the Chinese juices. The couple I have tried as samples we horrible. I don't trust their juice. Their regulations are not nearly as strict as the USA's and Europe's. There were two reasons why I started DIYing my juices, I wanted the freedom to play with flavors, and it is more cost effected on my budget. You're going to save the most by buying gallon jugs of PG and VG and the larger quantities of Nicotine.
I was a pack to a pack and a half a day smoker. That's nearly $300 a month on analogs, that's not including my boyfriend who was also a pack a day smoker. Since we've switched, the amount I've spent on the bulk purchases and all the flavors I've gotten so far and have coming, I haven't even spent what we would spend in a month's time on analogs.