which battery is cheapest per kW (I DO NOT mean kWh!) at which you can charge it?

I am looking at which battery is the cheapest per kW rate at which it will accept charge.

How much charge will A123 cells really accept?
If I calculate it for 4C it ammounts to 214 USD/kW, with 2.3Ah 3.3V 26650 cells at 6.50 USD per piece.

They write the max charging rate is 10A, which if calculated per cell is a little more then 4C, but: the smaller 1Ah 3.3V 18650 cells are also rated 10A, does it mean that they really can charge at 10C? Can you charge the smaller as fast as the larger, or maybe you can also charge the larger at 10C which would be 23A per cell? If both of them charged at 10A, then the smaller one, which costs 4.00 USD per piece would be better value for money (as far as USD/kW charging rate is concerned), resulting in 122 USD/kW.

How fully they can really be charged with such rates, will they charge to 80%, to 90% or 95% or how much?