>> I’m over 30, so wonder how wise it is to invest the time/money learning certain skills.
Absolutely wise to invest the time and money (time more than money; a lot of what one can train in can often come for free or at a very reduced cost).
>> Def hear some horror story of older guys in tech.
Let me start by saying I am an older guy in tech.
That being said, the #1 killer of tech careers is skill stagnation. Older guys frequently let their skills lapse and coast on a decade old skill set until they are worthless to their team / organization and then they're put out into the street with obsolete skills and bills to pay. I have seen this with my own eyes (and made a personal determination to not make that same mistake).
If you're in IT (or virtually any technology for that matter) then you should be learning EVERY day (or at least every week). I like to think of IT as a trade. Tradesmen (and women) hone a skill set throughout a career. The same goes for IT people.
As you get older you get slower and cannot learn as quickly as someone younger. On the other hand, life / career experience season your approach to learning (i.e. you already know how to learn and most likely have an instinct to know what is real and what is a fad). If you're used to constantly upgrading and honing your skill set then you know the routine. You can safely predict a training outcome before you even start it. That is the benefit of age.
All of this predicates on having a desire to be in a technological field for the sake of the technology. If you do not like what you do then you're not going to be motivated to learn it (no matter how much money it earns you).
For me personally, I have no interest in graphic or web design. Therefore I do not try to learn it. I use my time to learn what my IT shop is using and MASTER it (I already like what IT we use). If I am certifying in IT less than a half a dozen times every year then I am slacking off.
For you personally, I recommend the same. What do you like to do? Find those facets of IT that you enjoy and then go for it.
If you're in technical support, check out the DoD IAT certification tracks (see link below). Having an IAT level of certification can give you some career mobility. Also check out ITIL certification.