Let's say you have a small commercial shipyard lying around and nothing else particularly pressing to do with it. Let's further stipulate that you need maintenance supplies, and your industry is busy right now with more pressing things, or that you are short of Uridium or Gallicite (needed to make the supplies you need).
Behold, one of the the silliest exploits I have ever found in any game:
1. Make a ship that is nothing but a bridge, an engineering section, and a crew quarters.
2. Add Maintenance Storage Bays. A lot of them.
3. Make said ship (it will be CHEAP).
4. Transfer the 1000s of free maintenance supplies back to your planetary stockpile.
5. Scrap said ship.
6. Lather, rinse, repeat. You actually recovery the maintenance bays, but they don't seem to cost anything, give anything for scrap, or shorten the build time for the next one (bummer).
Basically, for the one-time retooling fee, you can make thousands of maintenance supplies for 3/4 of the cost of the ship. . . the one I tried cost 60 duranium and small change (less than 10) of mercassium, neutronium, and corbomite, and I got 46,000 maintenance supplies out of it. That is, by the time I scrapped the ship, it cost me about . 001 duranium per maintenance supply and about . 0001 or less of the other stuff.
Silly? YES. Funny? Well, I thought so. A silly exploit of the fact that "maintenance capacity" comes full for free.
As far as I can tell, you can also immediately take the MSP from any new commercial ship, too (they will never need it), but that's such a small amount as to be pointless.