If I remember right, the requirement is for a MAF vet to inspect the shipment 3 times over the quarantine period.
With freshwater fish to stock a tank, or a couple tanks, how many fish are you going to need? Let's just say for simplicity you're wanting about 200 tetras fish averaging $6 retail. That's only $1200 worth of fish to buy retail. Say you get the fish themselves for an average of a buck each, unless you can set up the quarantine for $1000 it's not worth it just to stock your own tanks.
Marines, you could easily get 100+ pieces of livestock that would probably average conservatively $75 each retail. That'd be about $7500 total, Probably cost in the range of $25 each or less for you to buy them to import. Leaves $5K to set up a quarantine facility. Makes MUCH more sense when you're talking those kind of prices.
Now, if you're doing it for reasons other than just financial, that changes everything.
Uhhh...What was my point? Did I have a point?