Back to the topic–
No, you’re not wasting your time working with Blender. Blender has the same tools as the “big boys”, just implemented in a different way. Since you’re looking to make 3D a career, though, you should eventually look into what software the places you want to work at are using.
“3D” is a big field, and some skills are portable from app to app, some aren’t. The fact is, if you can animate a CGI character so that it seems to think, live, and breathe in Blender (more a matter of acting than of tech or tools) then you have skills an animation/games/commercial house is going to be interested in. That’s a portable skill. Same goes (but to a lesser degree) for lighting, texturing, and modeling. If you can do them well in Blender, it’s a matter of weeks to pick up any other app.
This is not the case with rigging, or pipeline tools, or shader-writing, or any of the myriad other application-spacific jobs out there in the 3D world. If the job application asks for your Maya rigging skills and MEL script writing is a part of the brief, there’s no way Blender will help. It might make it quicker to pick up the necessary skills, since at root, it’s all pretty similar (that’s mathematically speaking) but it won’t get you through the door.
That said, there’s other stuff to take into consideration, as well. I assume since you’ve been cooking for 17 years, that you’re at least 30. While this isn’t the case across all fields and all houses, age-discrimination is a factor in some of the “cutting edge” areas like games. The assumption is that an older person with a family will be less willing than someone younger to put up with the crepes that they put you through with crunch time schedules and the like. Not to mention, with teamwork being all-important, you’ll have to work reallllllly well with people whose average age is somwhere south of 25, especially when you’re starting out. Granted, age-discrimination is illegal, and most companies won’t admit to it, or even practice it as a policy, but the fact remains that the break-in level of a lot of 3D is very much a young person’s game. Your experience with kitchen work will likely prepare you for it and give you ideas on how to work within that sort of environment, but it’s best to be aware of it in advance.
So, in sum, Blender is a great tool to get started in 3D, and even make your demo reel if what you’re interested in doing is character animation. If your interests tend more towards technical direction, though, I’d recommend learning more about the field in which you hope to gain employment and see what apps are commonest there. That can easily wait until you’re in school, when academic discounts will make the prices much more reasonable and you’ll have more information and experience to draw on to make your decision. In the meantime, absorb all the knowlege you can, about every aspect of the field. Check out the CGChar site to practice your character animation, read the other forums and magazines to see who’s hiring and what they’re looking for (the latest issue of 3D World magazine has a big article on managing your career in 3D from internship to management. It’s the issue with the green girl by Blanche on the cover).