Is there a skill in runescape that i can get to get 99 in about 30 days if i play a lot?

im going to become member for another month and i already got 99 fletching in about 17 days so i was wondering if there is any skill i can get to 99 easily... i would prefer a skill that i can earn profit instead of spending millions of $... i know prayer with guilded altars are is easy to train but i dont have that kind of money....while im at it.. how long does it take to get 99 construction? so plz help :) i would prefer a skill that can make you easily get money when 99 :) ty!!!