Based on my experience:

- Option 1 (direct) - cheaper if heavy items. If different sellers, must order together in the same checkout and will pay all cost upfront including shipping.
- Option 2 (consolidated) - cheaper for not so heavy shipment (less than 2kg or so). Only pay for the items at checkout and shipping will only be quoted later when they arrived at warehouse. Then you decide when you want them to send out the entire batch, and you can add new order in the meantime. They can keep the items in warehouse for free for some days (i forgot how many). If exceed the days you need to pay the 'rental'.

- Both options allow you to buy from different sellers.

- Example from my experience: 1) Shipment A, I used Option 1 and was quoted ¥55 for overseas shipment. It actually weighed 5kg+ so if I use option 2, it should cost ¥100++. 2) For shipment B, I was quoted ¥89 for Option 1. It actually weighed 1.8kg so Option 2 had costed ¥44.

- You might not know the weight to decide which option to take so you will need to estimate yourself (whether your items are heavy or light).

- Option 3 is almost always most expensive but probably fastest because each seller will send them separately and no need to wait for other orders to arrive at warehouse.