Need advice !

This question is more directed to the bitcoin miners. I have been Bit-coining for about 8 months now and I really enjoy doing it. The only problem is I'm not making any profit, long story short I have spent around $1500 and only made $ 500.00/ I have 4 miners pumping out 450 gh, and on a good day I might make .01 bt which means I will most likely never see a profit with my current set up... So here are my questions;

1) Is bit coin mining dead ?, should I though in the towel.
2) If it is not dead, should I buy a really big bitcoin miner $2000.00+, or lots of smaller ones ?.
3) What should I buy next and where should I buy them ?.

Thanks for the advice.