Well i would, as i usually due, recommend financing with a downpayment, but since you're only 5' 83 lbs, i'm guessing that you're under 18 and hence can't have a credit card....in which case it might not hurt to pitch the idea to your parents.

anyways, that way you could afford to economically expand your budget without depleting your bank account.

otherwise, i'd go with what freeridin' said and upgrade the hardrock. if the frames in good condition, you might as well, especially since you're already used to and comfortable on it.