OK to start off this idea has been around, just making sure people are aware.
Prereqs:
Be able to get to Rabao
Have a mule (this is not ideal for your main, you will see why)
8 or more free inv slots on your main
empty delivery queue
Items Involved:
Water Jug- Furniture- STG:2 +water - Cost 184 Gil
NPC Involved:
Scamplix- NPC Gob in Rabao(F-7)
Spirit Singer- NPC Delivery person in Rabao(K-7)
Basically the process is simple. since the water jug has 2 storage you simply buy 50 of them and gradually send them to your mule. This works well because most times your mule is in a starter city and will never leave. (this is a bad idea for jeuno mules and main char's because you will have 0 Mog Safe space when you are done, but you will have 100 Storage spaces which are not accessible from outside your original home.)
As you send all the jugs to your mule start moving items into storage from your mog safe. From then on use your storage instead.
Final cost for me was 184 * 50, which is just under 10k.
Why should you do this?
Well if you are like me you save everything, but what ends up happening is you get 1/2 stacks and 8/12 of some items and they just sit there taking up space. Now you wll have double the normal amount and won't need to throw away extra's etc. And the cost is far less than doing the mog expansions, although ify ou do those too you could have up to 160 storage.
Anyway enjoy, use it or don't just figured i would pass it along.