It's not an easy at indeed. I doubt you'd find anyone who would do it for less than $400, probably would be even more than that. That might be worth it for something valuable but for a Squier, probably not. Unless you *really* love that bass that much that it would be worth it in *your* eyes because you know you'll always keep it.
BTW, I just did this to my first bass, also a Squier, just a few weeks ago. Here's the thread if you want to see what's involved in changing a truss rod.
Fixing up my first bass - Squier P