Millions is a bit high for the cost of a cubesat launch. A number of places estimate 1U cubesat launch prices as low as $40k, but probably 1U-3U you can expect to pay low hundreds of thousands.
Yes, It is not on the millions but on $ 60k per kg according the Satellogic CEO [1]. The millions number is if you want to launch a constellation of satellites.
Other open software software (not updated for two years) that was used for three nano satellites is here https://github.com/satellogic/canopus .