My fear of being $200k+ in debt was really holding me back from choosing HLS (and a couple other factors too, but debt most of all). I have several lawyer relatives and they believe that the debt is worth it. They know the market right now and what it's like in good times, too. One of my parents even encouraged me to turn down a full scholarship offer from his/her alma mater. A firm lawyer I know well encouraged me to aim for higher than HIS alma mater and higher than my original "goal" school, too. And I could go on and on--I've gotten this same advice from every lawyer I know, in a variety of private and public sector jobs, except for two (who were hesitant to push for HLS because the alumni they know thought it was a miserable place over a decade ago).
HLS is a "safe" bet for me despite the debt because I don't know what I want to do professionally and whatever field you pursue, you really can't go wrong with Harvard. I'm still scared about it, but knowing all this alleviates my worries a little bit (and the other factors that draw me to Harvard more than balance out the concerns).
That said, I definitely think it's a personal decision and everyone will have different priorities. (And, full disclosure: if I had been offered a full scholarship to another T14 that I liked a lot, that might have changed the game, but that was not the case.)
I don't think there's anything wrong with approaching the teacher. I think most lawyers would be willing to advise you and most teachers are happy to advise students (at least at Harvard they are!). Plus, you should get in the habit of approaching professors if you aren't already, it'll be a good habit to bring to law school