A good advice is to dig shells, as all the jobs approximately give you the same gralats, depending on the average, the quality and amount of the prize for completing the job, the average is nearly the same, you can dig shells and sell in small amounts 1 trochus for 2 aerolatas, both give you 3 gralats for each shell, instead of getting 300 gralats for 100 trochus you would get 200 aerolatas which are equal to 600 gralats, doubling up your benefits, use this method by trading your trochus for the aerolatas in small amounts.