There is no such thing as free shipping. The shipping company doesn’t work for free. The cost is just bundled in the price and passed on to the end consumer without being itemized. True for most everything, not just batteries. Just pay attention to the total cost, DDP, delivered to your door.
Cells in stock in the US is hit or miss as stock sells out. You have
@Signature Solar and Rebel
@ashelby as US based “turn key” battery suppliers who can predict, with some accuracy, when their next container may arrive and clear customs.
For raw cells you have
@Michael B Caro trying to get his backlog cleared and keep some US stock.
@Season is a new player trying to get stock through customs.
@Amy Wan (Luyuan) is a trusted China based shipper of raw cells who has been here a while but no US stock.
@HighTechLab and a couple others are trying to fill the void between complete DIY and turn key.
Personally I would avoid Big Battery company at all costs.
All of these, and more, are discussed on the forum.
Hope that helps and welcome to the forum !