if you hit ebay you can get a set inc some vinyl for around 200 pound upwards, depends on how much you want to spend tbh
cd decks start around 100 plus mixer etc so alow 200-300 plus
to kit your self out with top spec stuff you can spend thousnds, mine stands me in around 5000, and still not finished
something like this would get you started
http://cgi.ebay.co.uk/FULL-DJ-SETUP-...ht_1522wt_1165
thats the sort of price id be happy with iv always wanted to do it just never had the time but i need another hobby as the winter is coming and fishing is shit in the snow lol but do your next door neighbors moan a lot coz iv already had 2 letters about my music being loud and 3rd time they will take my cd player away apparently how do you get away from the aggro