I calculated the cost of the pack from the data at $140 for 1kWh. I guess I shouldn't have included the kWh in the divisor but

(10000x3.7V2710Ah$0.014) <- total cost of the pack

/

10 <- normalize to 1kWh

=

$140

This makes more sense than battery costs dropping 99%. I was confused by op, and wish it were true. It’s more like 10x solar than 1/10th solar.