If micro fine gold wasn't worth getting most of the worlds largest commercial gold mines would have to close. I'll take an ounce of fine stuff over a gram of coarse any day.
Of course if you don't have the equipment or skills to catch finer gold, you could be throwing away a large portion of your possible take. Local beach gold on a friends mining licence is very fine 60% or more of the gold he recovers is not visible to naked eye.
Some places have very little fine gold, others have only fine gold - waste of time trying to catch what isn't there, waste of labor and fuel not catching what is there.
Getting onto some good moss, about fifty tiny specs per pan - could get an ounce or more in a week - if you have enough good moss. The moss I'm talking about wont burn very well as its wet and full of sand. It has to come from a river where plenty of fine gold is present and moving in flood times. It will be lying fairly flat and will have gravels swept over it in a flood. If you are not able to process a cubic yard, or don't have a cubic yard of moss that has an average of fifty tiny specs per pan visible - then you are not going to make enough to make it worthwhile.
Also if moss was no good at catching gold - they wouldn't make an artificial version for gold miners to line their sluices with - but they do.
Some folk could starve in a restaurant - don't join them. Nuggy