Gemini 3.8 flash has better rates. $0.75 per million input tokens and $3.75 per million output tokens.

Compare that to Muse spark 1.3

$1.25/M input, $4.25/M output (without data sharing) $0.10/M input, $0.20/M output (with data sharing)

It is dirt cheap, but only if you are willing to share your data with meta and allow them to use it for improving their models and products.