in my case at least i only seem to get valuable items when i take a large shipment has anyone else had the same experience?

What kind of shipment? Artifact or minerals?

ooppp sorry minerals i just seem to get the million credit or half million credit when i really empty out. i know the artifact probability thing, by the way does the space for artifacts go up the bigger your ship is , ie over 6000? seems like its just you and me here today bro so thanks for the answers

Artifact sizes are fixed regardless of rank level,ship size. Artifact with many uses use more. Uses 1 = size 1, Uses 2 = size 2. Some artifacts are bigger though.

Minerals, I guess it mainly depends on level and luck.

may seem that way, but only because your odds are greater when you sell more at a time. like if you sell 1000 you have 1000 chances to get a higher value mineral etc. well 4000 and you get 3000 more chances to win the lottery with the minerals.

that makes sense almost to simple dahh on my part