Regarding payloads, it depends on what you're launching. If your satellite is 4 tons, then you can directly compare the price of a Falcon 9 and an Atlas, for example. It doesn't get noticeably cheaper to fly a rocket at less than full payload. Obviously, if you're launching something that exceeds Falcon's maximum payload then it's not an option, but given their campaign, there must be a lot of lighter payloads going up as part of this program.