a few weeks to a month to cycle. how will you start the cycle? you will need to add an ammonia source. a raw shrimp form the market, some pure ammonia, the 25-35 pounds or so of live rock.
just like a fresh water tank, beneficial bacteria resides on surfaces of a salt tank as well. the more surface area the better your bacteria colony will be and the better your tank will process nutrients.
i would buy the rock. if you look on craigslist you should be able to find someone selling everything off and getting out of the hobby. there you may be able to purchase the rock for a dollar or two a pound.
some sand and the test kits and thermometer, refractometer...etc.
maybe a hundred dollars if you are super thrifty.