If you really want to stay in hisec, then what I’ve noticed is that systems adjacent to low sec entry points are often short on “staple goods” that people want for their low/null sec operations.
I’m not going to name any of these locations, because then I’d be inviting competition. A general idea, though would be say: near a mission running place. Like one where you can do level 5 missions, or a concentration of level 4 agents.
Just for the convenience of not having to make a trip to Jita, people will pay a higher price. You just have to figure out what the mission runners are using. (Maybe go to where the mission is and do D-scans to see what kind of ship they like to fly… etc…)
But instead of hauling the items from Jita, it’s probably easier to haul minerals/ore out there, and make it locally.
I’d guess mobile tractor units get at least a few sales. Not sure how many, though. (And it makes a good use for your PI).