Wow. Thank you all for your honest and thoughtful insight. I truly appreciate it and it's given me a lot to chew on.
KungfuRabbit
I aim to be more of a post-apocalyptic survivalist (long-term survival and rebuilding), and would likely need to rely on luck and wits and either go solo and hunker down out of sight, or make friends with day 1 survivalists, trading skill for additional protection ;)
Your point about the oversaturation of certain science degrees, is a small part of the reason I want to avoid them. Also if I ever do decide to move up in my current field (which would be actually working with animals), much of the applicable knowledge I would gain from a Biology/zoology degree, I could study on my own or learn on the job, which I already have in part. My zoo puts new-hires working in animal-care departments, through some online zoology courses as part of the onboarding process, as quite a few people hired into the field do not have much education in natural sciences...simply having a science degree, practically any science degree, is all that's required in many positions. That makes sense because people who are finally hired as keepers, animal nutritionists, or clinic staff, have worked a year or longer as interns, and so it's assumed by the time you are hired at an AZA facility, you already have the experience desired, you just need that BS to get your foot in the door. I don't have enough of a desire to be a zookeeper to jump through hoops (and spend that much) on a natural science degree. If it happens in the future and I can do it for a couple of years, or seasonally, or on a part time basis, that's great; but I'm not going to invest alot money and time to do it.
I should have been more clear about my work/retirement goals in my OP, as it differs from the norm. I don't want to work year round, or rather I don't want a job that requires me to work year round. Over the years I've had a mix of working full-time, and cobbling together a living from multiple streams of income. I've come to realize I like being a cobbler. I like the idea of working a project, or a seasonal gig, followed by a break with a length of my choosing. I am tired of being tied to a job, only getting a few weeks per year away. I don't want to retire early, I just want to not have to work for several months per year. I could see myself working full-time in a job that personally fulfills me, but only for a couple of years at a time, and not as a build up to a long-term career. Also, I plan on making a good chunk of my income and assets, from real estate.
I like the idea of being the one to do the building, and have considered getting some type of construction degree or even just a contractor license (and I am still not ruling that out). But I do ultimately want a science degree, as I feel that will open more doors for me in the things I am interested in doing in the future of which I admit there is a lot. I am not going to go back to school after this last shot, so I guess I am trying to predict the action that will offer me the most options in the future, particularly since I plan on job juggling.
I am willing to spend up to $35k for a degree (but hopefully less). I won't have to take certain core classes as I already have a BA. And my full time job offers tuition reimbursement for courses towards a healthcare degree (which would include some math and science), so I could use that for some of the pre-reqs. But once I do (if I do) get accepted into an engineering program at my local uni, I will need to stop working full-time, but plan on continuing to manage my rental property and work part time at the zoo. I plan to use a combination of savings, income from rental and part time job, and a cash-out refi on the rental property (before I quit working full time of course), which I would keep in a CD that will hopefully earn me back over half the interest I'd be paying on the addition to the mortgage, essentially giving myself a "student loan" at 2-3%.
I am still formulating my responses to everyone elses's replies. You all gave me so much to think about! Even if no one reads my responses (I know I am long-winded), it is really helping my thought-mapping to work through the questions and advice.