There are some gambling sites that you can bet a really low amount but that's your job to find one, you can search it in google and etc... but the problem of gambling really low amount is that you have a specific amount to withdraw it and sometimes its pretty high and its hard to win that amount because your losing most of your BTC and the betting is really low, that's my opinion on betting on really low amount of BTC but we all have different opinion and all of us are different. If you can bet all day until you win and can withdraw it, good for you but I have no patient on that.