Here's what should all be unlocked to get the best results:

Barrack Tier 3 for the workers to fully load up the storage slots
Storage Shop Tier 3 to access all of the upgrades to your inventory (and car. but car isn't needed)
Large Backpack to get up to 20 materials per slot

Skills:
Professionals to be able to hire all four Tier 3 workers
all Worker Materials so they grab as much as possible
all Workers Payment to save on cost to reduce number of runs (they can survive on lower pay, right?)
all Equipment Slot to have full access to your inventory
all Material Prices to also reduce the number of runs

Higher Prices can help but might not be required. it all depends on if you feel lucky and it can help reduce the number of runs. if your level is very high and you've unlocked every single other skill, why have you stopped on this one?

The most important part is to hire all four workers that give the high-priced materials such as Titanium and Stainless Steel. If you have any workers hired that don't give those kinds of materials, you should fire them for now, since they will clog up the Worker's Storage and you will be making far more trips back-and-forth.

It really is all about sleeping the days away once you have the unlocks needed.

What you can do is sleep 3 times, go to the Worker's Storage, collect all materials there, and either go back to the bed to sleep 3 more times or sell that inventory and then sleep 3 times. You may sometimes see a notification that there is no more room in the Worker's Storage because they've filled it up. That's both lucky that they got a lot of materials but unlucky because you may have missed out on about on a couple hundred or, at worst, $1000. It's up to you if you feel like doing 2 sleeps instead of 3 if you can deal with more back-and-forth.

Per full 9-sleep run with doing the 3-sleep and collect method, you should see about $25-30k per run. Each separate 3-sleep inventory *without* going back for the full 9, you might see between $7-12k per run.

The last thing to mention is that this will heavily inflate your day count, if you even care about that. For example, I started it around day 67 or 68 and ended it at day 190. I mention it might take a couple hours but your time will no doubt vary, depending on how much you have left to get.