I think it's lose to much, must control the budget before lose to much. I think lose until 0.005 BTC is ok.
If not set budget and control like that, will lose until 100 BTC. For my suggest that amount (50 bitcoins) better do invest.
yeah if we have more than 100 btc then losing 50 btc is not be a problem. but most of people which only have less than 5 btc have big dreams to win much of bitcoin from gambling but some of them is loss more than half from the total amount they have. and yes i am agree to use 50 btc for investment because at least we can see that our bitcoin can works properly and we can have additional income so this will be a good lesson to us to prevent this so we can control our emotion.