A luxury is only worth the expense if you notice the difference.
That is a key concept, right there, and a very well worded one too.
I research, decide upon and buy my vaping equipment the same way most of us here do. What do I want in a specific type of product (tank/mod/mech/battery/etc.)? Starting with the basics: design, materials, build quality, features, compatibility, cost to use over time, etc. Which of those is more important to me, which is less important to me. With all of that, personal value (opportunity cost vs. price) can be determined. Divide opportunity cost by price. If the result is zero or higher, then it would be a justifiable purchase. Lower than zero means it would not be a justifiable purchase. This is one of the most basic aspects of macro-economics.
In more depth, features tend to take the most time to research and decide upon simply because the list is longer, even when feature set isn't a person's top priority.
Most of my vaping purchases were fairly easy choices for two main reasons.
(1) You people here at ECF have taught me so much that I can look at most products and quickly make a well-informed decision. And so far, I've been very satisfied with almost everything I've bought over my five month vaping career.
(2) Most of what I've bought have been low cost items. $7 for this, $20 for that, and such. Screwing up a $200 purchase obviously hurts more than screwing up a $20 one.
Predictably, the product that took me the most time to research and ask others about has also been my most expensive one. It's my eVic-S ($159 for the kit: eVic Supreme, Sony 18650 VTC5 2100mAh battery, passthrough cable and wall adapter). It's only been on the market for a few weeks, but I'm really looking forward to discovering the true value (market and personal) of this device over the next several months as more people buy them and compare them with earlier products in the same category. I haven't owned the first eVic model, but comparing it with the new Supreme model by the reports of others, and by the data I've found online, the difference seems to be extensive. I've heard a few people say
"The eVic-S? Yeah, I bought an eVic last year..." Not realizing that it's a very different animal, mainly (and significantly) in build quality.
It's all about the difference between making an informed decision and making an uninformed decision. We'd all prefer to do the former, but it's hard when you can't actually own "one of everything", and then decide first hand what you want to keep and what you want to sell (or better yet, PIF). Once I sell some books and make my first billion, I can do just that. (Tongue firmly in cheek.
) Until then, I'm limited to research and recommendations, and somewhat to the luck of the draw.
Which is what makes the advice we give to other vapers, new or experienced, so important. I haven't been vaping long, so I'm still learning much more than I can rightly teach. But the help I've gotten from all you folks has been invaluable to me for everything I've vaped with so far.
THANK YOU for that. It makes me realize the importance of giving quality vaping advice to people, especially so for those just switching from smoking to vaping. Remember, when you give out vaping advice, you're not just helping people buy the right products for themselves, you're helping to potentially save their lives, as well. A person who receives and acts on bad advice - or none at all - may very well quit vaping after a couple of weeks and go back to smoking, with potentially disastrous results.
I'm very proud to be part of a place whose members give overwhelmingly good advice to people who come here looking to make their lives better, not to mention longer.
As always, you people rock!
Thank you very much for the explanation! Now, this is something I definitely did not know. 
