I've basically traded off the expense of buying new coils all the time for the expense of buying more juice. I'm starting to think that I went backwards as I could at times keep a prebuilt coil in my rig for a couple weeks, and one 15ml bottle of juice might also last me a week. Now I'm going through a 15ml bottle of juice every 2 or 3 days using the subtank with a 0.5 to 0.7 coil. At this rate it's going to start adding up to what I used to pay for my stinky cig habits (considering that we always bought "native Indian" cigs off the reservations or at Indian Cig stores and that was one of reasons to quit, the overall price of the stinkies)
It's definitely time to start making my own juice. I have simple tastes, I love salted caramel by Jiu Jit so I figure I'll start off by making some sort of caramel graham cracker type of juice, or figure out what to use to get that "salted" taste and make my own salted caramel, it's just getting too expensive to buy store bought juice when using this subtank and a 0.5 coil.
When we first started to vape, my partner and I decided that we wanted to make juice to sell to the retailers but never got around to it. We got our papers in order, had professional logos designed, came up with catchy name etc but just never produced the juice. I think it's time and if we do stumble upon something that is really really great tasting, then maybe take it to the next level and invest in renting kitchens that are used for this sort of thing, since our own kitchen is too old to produce juice to sell.