OK, first of all, WELCOME TO THE GROUP!!

Investing only a $150 should be last of your concerns... honestly... to be semi proficient at playing the violin, you'll need to devote time and effort to it. Just because you have a violin in the case in the closet and take it out once a week or twice doesn't mean you'll be able to play in 6 months. I personally have been seriously practicing, and I mean practicing... at least 30 min to 1-1/2 hrs at least 5 days a week, every week for the past year almost (feb 14th will be 1 year) and I have semi mastered the bow and the ability to play some recognizable tunes. How many is irrelevent if you can't play at least one flawlessly and that takes hands on practice. It's far better to practice 1/2 hr a day than try to acomplish all your practice time in 2 hours on Sunday. It's a real hands on thing and the value of the violin will seem trivial when you figure in the lessons (if you choose to take some) and time required to 'sound decent'. Some people are quite content playing for themselves and others need to accomplish a concert or orchastra position which requires an almost lifetime comitment. Some catch on quite quickly and master a dozen tunes in the first year of playing...some...like me, not so many.

I play for myself and feel I could've done better in the note reading department but I play by ear and play well enough for "me".

Once you get a violin, you'll treat it like a little baby, seemingly scared to hurt it or maybe drop it but you'll soon develop the required concentration to handle it well. You'll find yourself skipping dinner and such things as a movie to stay home and practice, if you truly want to play the violin. You'll break strings and ask a million questions that have all been asked before. You'll learn and then turn around and help the new comers to the instrument and share your wealth of education you learn along your path of playing expertise. You'll want to either sell it and never look at another violin, or you'll be so enchanted by it and the potential for sound to be developed that you'll sell it and upgrade to a better one, or you'll keep your 'first' and buy a second and be so proud most people won't understand, but the others that are just like you will.

It's a long road to proficient playing but very rewarding if you commit and learn. It's nothing like guitar where you can poke your fingers down between frets and play a note, no sir... this takes muscle memory and thus becomes automatic to 'stick the note' because of lack of frets, (on the conventional violin anyway) and then there's the question of strings, rosin, type of bow, even talk of temperature and humidity and playing outside in the sunshine...then there's the question of whether you should play electric or acoustic, ( I suggest starting on an acoustic one) whether you can play with others, jam with a band or friends that play... what type of music do you fancy to play on it... comtemporary, country bluegrass, classical, cross over like David Garrett does or hip hop stuff typical of Lyndsey.

So many questions to answer from your simple question you asked. 

Whatever you choose to do, you're in good company around here, all of started somewhere and all are very helpful... because since you're here now asking...

you're part of our family.