Thanks for your rely. I had a feeling I was pushing my luck with that request. But ultimately I'm wanting a 30 min flight time with a payload of 600-800 g. Thanks again.
There are folks with near an hour flight time but that's with a payload of only batteries. Longer flight times are possible if using batteries sequentially and dropping depleted batteries to reduce the payload. Realistic expectations for the typical copter is between 10 and 20 minutes. This isn't 100% accurate but it can give you ballpark numbers for different configurations.