A faucet for example could cost you more then +1000$ because If you are serious about it, you should hire designers, make it unique compared to others (competitive rates etc.) and mostly, protect it from bots and multi accounts (a Captcha is not enough), this is the only way to insure that both you and your users will make profit. A gambling site (which I don't recommend even If it was easy to start) will clearly cost much more, development, security etc. are top priority otherwise you will get hacked in no time but most of the funds should be for paying users.