After a short hiatus, this thread is now back in business.
That's getting into complicated large orders and DIY mixing territory. If you just want to buy a 30ml bottle from them, it's $15 or $0.50/ml. This is not meant to include all the specials or bulk deals that a site offers, just a simple cost per ml list for small and large bottles.
Added new supplier - Vapor Renu
At ~$.24/ml for 30ml bottles, these guys are the cheapest US mixing shop around. I think the current price is a grand opening sale, so I'll update the chart if they go up later.
Here's a sortable, searchable chart of all the US-based e-liquid suppliers I could find. Data includes cost per ml for large and small bottles, along with shipping costs. People looking for juice at a particular price point may find this useful. Note that for whatever reason, it sorts the shop links by URL, not by name. For that reason, a few shops are not in alphabetical order.
E-Liquid Cost-per-ml | Socrata | Making Data Social
While TV is certainly a good deal if you're willing to do some mixing yourself, it's squarely in the realm of DIY. You need to buy multiple bottles, plus empty bottles, then measure and mix. If you're willing to go that route, you can certainly save some money with TV. You can save even more by mixing the flavors yourself, as anybody in the DIY forum can attest. But if I were to include all the DIY options from all the sites out there, the chart would be a mile long. I wanted to keep it as simple as possible while still being useful. Many people (most, I would think) just want to buy a bottle of ready-to-vape juice and not have to deal with mixing and whatnot. This list is for those people. And if those people want to buy pre-mixed juice from TV, it costs $.50/ml.Through no fault of yours, the $.50 price for Tasty Vapor is misleadingly high. In fact, TV juice is (or, at least, can be) the least expensive out there, but the way they sell it makes it difficult to get a handle on.
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How you represent all that on your chart ... I don't know. To me, $.25 seems about right; and certainly closer to the reality than $.50.
Added Vapor Junction.You might look at VaporJunction.com, Alabama, $7.00 flat rate