Is independent research a good long term goal for a bachelor's degree holder with experience and interest? Bear with me while I put some biographical information here.

I'm a bachelor of engineering graduate from India with approximately a decade of work experience in design, engineering and project management. I've got a real fascination for the following subjects:


Optimization methods
Chaotic and dynamical systems
Data analysis and statistics (a field in which I work - as a quality management professional)


I have presented a couple of papers in international conferences in the first subject - based on work I did by teaching myself optimization methods. Learnt the ropes on researching papers/work, contacting researchers, running my own studies, writing concise papers, over many attempts in unpublished papers. I have only read books and papers on the remaining two subjects (#2 and #3) for over seven years but haven't really contributed anything significant or original. 

Since I never was in the right financial state to pursue a masters or a PhD, I never earned one. I turned down an MS admit at Duke in 2010 for financial reasons too (didn't manage to secure funding). I considered and visited Indian universities including the IITs but find the entry barrier high for any univs worth going to, because I have a 7.0/10.0 GPA on my Bachelor's degree. Moreover, I hate going back and asking for recommendations from professors that I share no common interest with or who had no bearing or influence on my technical interests whatsoever. My mentors have all been in the industry, and all MS/PhD applications seem to want only academic recommendations, which I thought was stupid.

Having read a number of reports and accounts from researchers on the troubles PhD scholars face and the standard of life, I'm inclined to think that I wouldn't be happy giving up my job and my lifestyle (and compromising my wife's lifestyle) for a decade of research which may or may not lead to a PhD. I love the subjects but I'm looking for a way to learn and discover things in them without subjecting myself to the financial commitment that comes with a huge loan.

Is a life of independent research (something that is exciting for me personally) a viable way to move forward, or should I consider getting a formal research postgraduate degree? I'm eager to hear thoughts, advice, comments. Thanks for taking time out to read this.
It seems you have two options to weigh against each other:


Do research independently, viewing it more as a hobby than as your profession, or
become a professional researcher, which would require getting the appropriate formal education.


If you want to make research the most important aspect of your life, then option 2 would be the way to go. However, from your current biography, it seems that this may require more effort and changes to your life than you may be willing to invest. Getting a PhD is a definite requirement along this path.

If you go for option 1, it will still be possible to make research an important aspect of your life. It will be more difficult though to maintain sufficient investment of time in view of work and family commitments to keep things running.

Personally, I think that being a hobby researcher can be viable and satisfying in research fields where you don't need expensive equipment. While the examples I know mostly do something like locally focussed historical research or botanical/zoological research in their environment, it seems that mathematical or theoretical engineering topics will also be feasible for this. If you want to go that way, the internet certainly provides much more advice on being a hobby researcher than I can hope to give here. A link to start with may be this question on cstheory.stackexchange.com.