I believe it IS important from the beginning to develop the right technique. A lot of times, and for a lot of stuff, you may be able to just get by with a deficient technique that "works for you", but a few years down the road, if you start practicing more advanced and elaborate stuff (prog rock and metal, jazz, funk, fusion, improv., etc.), you will realize that your technique doesn't allow you to do it so easily and you'll have to rethink your whole technique and start over with a different approach to take your playing to the next level.
Something like that happened to me when I first learned to play bass: my teacher was an excellent upright player, but only a mediocre electric bass one(which I couldn't possibly know at that time). Although he taught me a lot of theory, sight reading, scales, etc, in an excellent way, he also made me develop some very bad habits, mainly on my right hand technique on the electric, which only after 3 years of studying and a change of teacher I realized that were flawed. So then I had to start over with a different (more appropriate technique) and it took me several months of intense work to be able to change it and get comfortable with the new technique.
And the problem is that this more appropriate technique, although it did improved my playing greatly, is not really that radically different from the first one I learned, and there are only subtle differences between both, which are not so obvious to anyone unless they are truly bass players, and not players from other instruments that happen to more less play the bass.
Also, I later realized that my older technique(with it's deficient string muting, wrong thumb placing and wrist angle, and free motion impediments) is something you can find very commonly amongst non professional/intermediate and amateur bass players, because a lot of them think is just like playing guitar but easier, so they don't take the time or interest to really find out and learn the correct way of playing bass. And the problem gets worse when this intermediate bass players start teaching bass to get a few extra bucks, so they spread this wrong knowledge and bad habits to a lot of new bass players.
Now, I'm not saying that you cannot find a musician that plays correctly several instruments, because I know a few that do( and there are also some pro bass players that also play guitar or keyboard at a very good level), but both of these scenarios are very rare to find, and there are far more teachers out there that have poor technique on the bass because their main instrument is a different one and they don't spend that much time developing their bass skills, so I would try to be careful to differentiate between each of these cases.
So my advice to you would be to save yourself some time (years), effort and money (on the long run), by learning the right technique from the beginning, doing some background check on your teacher prospects, and studying with a truly professional bass player and teacher, even if it costs more money or if it's farther away from where you live. In fact, there are even Skype lessons with a lot of truly great bass players out there, so really there's no excuse not to get a proper bass education...
Hope this helps.
