Start with a daily dose of good old P.T.: pushups, crunches, pull-ups and running.
Ten bucks will get you a good set of construction site/junk yard equipment: a couple buckets & some sand, a few feet of rope and a couple old tires, a length of pipe and half a dozen concrete blocks. Use your imagination, set a bunch of goals (reps, days, weeks) and if you motivate yourself to stick with it... buy a couple sacks of concrete!
You'll be amazed what you can do without spending a bunch of money. Your body will get as tough as your mind -- and you won't empty your wallet or have expensive equipment taking up space.