I guess since I am contracted through the local university to write and grade tests for introductory linguistics courses, I am technically working in my field at the moment, though it hasn't always been so (I also freelanced in translation for a while, years ago, but that was actually before I even had a BA). It's not really a career by any stretch of the imagination (the contract is up in by the end of December), but it's nice to be working on things I know. I get to slip in questions on Coptic morphology and whatnot, and then be crushed when the students don't answer them correctly (but...but...I made this for you!
), so that's...good, I guess. And it opens the door to teaching (I've already been offered twice; the only reason I can't accept is because of my physical condition at the moment), which is very good.
I know it's a cliche, but it really is true that if you do what you love, it's not really like working. I would be nerding out over languages even if I weren't on a monthly salary, so from my point of view the little money I do make is like a bonus that keeps a roof over my head, my bills paid, and food in me...and that's all really so that I can keep studying more linguistics without having to worry about those basic needs being met.
Find something you love like that, then do it. Life is way too short to be sort of committed to something that you will have put thousands of hours (and dollars) into by the time you graduate.
Edit to add: James, don't look down on less prestigious options. They may not be ivy league, but particularly at the BA level this is your introduction to the field (read: it's not worth much in itself) and the relative bump that you could receive might not be worth the price you're paying for it. I had a friend who went to Berkeley and another who went to SF State. They both did language-focused degrees (UC Berkeley Linguistics and SF State Italian). Now, several years later, the UC Berkeley grad works with "Hooked on Phonics" type software to help kids with reading disabilities and earns a modest living that enables him to live in the SF Bay Area in a modest apartment, with roommates to share the cost. The SF State grad works with machine translation in Italian (when not pestering me to move back to California and work in the company's Russian division...I can say "no" in many languages, but somehow it never sinks in)...and earns a modest living that enables her to live in the SF Bay Area in a modest apartment, with roomates to help share the cost. They're at essentially the same level, but I guarantee you that my UC Berkeley friend will be paying off his loans for a longer period of time than my SF State friend.
A lot of which school you choose will have to do with the quality of the department you'll be working in, rather than the reputation of the school overall in comparison to more prestigious universities. Don't be blinded by names. In today's world, they still matter but a BA really just gets your foot in the door for basic jobs (since it's pretty much like saying "I showed up and didn't break anything!", given how many people have one and are going after the same scarce jobs); it's not going to decide whether or not you're hired.